ChiefKwens' Road to 4As and OCREWatch
Hey, my name is ChiefKwen this thread was originally meant for the "Grow your grades" forum but that doesn't open until January/February so ill post it here instead. Currently I am studying the As-level subjects Biology, Chemistry, Maths and Philosophy. I was originally doing physics on top of that and regret leaving it . I enjoy going to the gym, sports( football, basketball and any sport that involves working in a team). I also enjoy going to a debate club, poetry club and drawing. I also plan to record on this blog extra curricular activities done e.g: Corpus Christi Challenge for Yr 12 students wanting to do medicine.
My Grade Goals:
Chemistry AS: A
Biology AS: A
Maths AS: A
Philosophy AS: A
(10/12/15) Class test Grades:
Biology AQA: (B) to (E)
On the biological molecules topic.
Chemistry AQA: B (25/34) (3 marks from A)Amount of substance/Ionisation. Need to improve on calculations
Maths AQA: D (32/60)
Need to improve on simple algebra mistakes and Coordinate Geometry overall. More past paper questions along with maths workshops.
Philosophy OCR: B (7/10)
( 1 mark from an A) on an evaluation question. To improve = provide more quotes to support my argument, and clearly link the question to the point being made.
20/01/2016: Class test Grades:
Biology AQA: (B) to (E)On the biological molecules topic. No test results since.
Chemistry AQA: B (25/34) (3 marks from A)
Amount of substance/Ionisation. Need to improve on calculations. No test results.
Maths AQA: A (52/60) (On the Differentiation/ Integration Final topic of C1)
I lost marks mainly on the finding the area of a shaded region and losing marks on the integration section for evaluating( x^3-10x^2+28x) )(Question 5C) at 3 and 1 rather than the integral of it.
Philosophy OCR: A (87%) on an ethics test and A(92%) (51/55)
Also very happy with these class grades even though I was slightly unhappy about the 87% and was aiming for higher. This test was mainly on definitions, and explaining concepts. Not in the same style that actual the exam will be.
My Career Goals
My ultimate career goal is to become a medical doctor. I am heavily inspired by Che Guevara and his works around south america before he joined Castro. I wish and hope that I am able get the Grades to apply to either:
University College London , Imperial College London, Cambridge/Oxford, Leeds, or Kings College London for medicine.
Thanks for reading any advice is appreciated .
Biology 07:58 to 8:44
Topic: Practical and Biological molecules test.
For biology mainly today I centred around the practical " Determining the effect of sucrose concentration on the water potential of potato cubes".
- My main area of improvement is refreshing my knowledge of what Independent Variables, Controlled Variables and Dependent Variables were. ( this is one of my biggest weakness, not to reviewing the foundation of the topic).
- I also completed past paper questions on the practicals. I lost marks because of:
-Not being able to find rate of osmosis
Then reviewed my previous Biology paper marks lost because of :
-1(a) I need to learn how to identify the Deoxyribose sugar, phosphate group and nucleotide in a DNA molecule
-1(a) (pg 3): I did not accurately write the whether the carbohydrates (Starch, Sucrose, Fructose, Maltose and Glycogen) were monosaccharides, disaccharides, or polysaccharides. Looking back it was a dumb mistake( i said fructose was a dissachride which lost me 2 marks)
-1(a) (pg 2): Revise features of starch which enable it to act as a storage substance. One feature could be starch's insolubility in water which means it can not be affected by osmosis and easily diffused out of the cell.
-2(a) (pg 4): Describe the information given by point A on the graph. Ans - Graph shows that 20 out of 100,00 people died from breast cancer when the percentage of fat in their diet was 35%. Lost 1 mark giving me zero marks out of 1 as I didn't include the fact that point A refers to one country.
-2(b) To gain a rate of something or death rate I need to learn that:
= Number of deaths from disease/ total population * 100 + death rate.
-2(c) I need more research into the lifestyle cause of disease.
-2(b) (pg 4) Have to remember what occurs as a result of competitive inhibitors e.g the are less binds between the substrate and its complementary active site on the enzyme. I missed that fact out gaining only 2 marks out of 3
2a(ii) (pg4) remember how to draw different monosaccharides.
3a(I) and 3a(ii) more past paper questions so that i can understand them more and know when to write about enzymes not being used up in the reaction.
Summary of Biology
Overall, a good result. More practice could be done on the whole biological molecules topic specifically monomers, polymers, and enzymes. My strengths are the biological tests but my weakness lies in energy storage in carbohydrates which needs to be revised. Another weakness is graphs. I plan to do more work on those.
websites used: www.scribd.com and http://www.alevelbiology.co.uk/as2.html
10:04-11:40 or 1 hour 36 mins.
during my free periods
12 minutes where spent with a friend of mine quizing me on the general formula and structural formula of functional groups. Quizing and challenging friends is not only fun but helps me remember things more after i read them. So what helps me is passive recall ---->passive recall then active recall.
I also spent and 75 minutes on a self assessment exercise mainly on : Dot and cross diagrams, metallic bonding, covalent bonding and dative bonding.
Have yet to mark it because I had to do assembly. But judging from my last assessments (25/34). I scored 6/11 on the Calculations section and 19/23 on the ionisation topic averaging out to a B. My weaknesses were:
-i need work on calculation questions for moles, concentration and mass all applied together.
-Certain aspects of ionisation confused which i'll edit into this post once I find my paper.
I did mainly mechanics worksheets in the mechanics 1 and 2 booklet. Working through questions which gave speed and bearing and asked me to express the vector in terms of ai+bj. I found the questions fairly straight forward even though so far I find mechanics more challenging than C1. Understood most questions, things to remember is to : write the bearings with three numbers e.g 72 degrees as 072 degrees, and the suvat (S= Displacement, U= Initial Velocity, V= Final Velocity, A= Acceleration, T = time) equations.
Score (29/37) for the homework which is 78% or a solid B.
Going through my MPC1 Coordinate Geometry test( 1hr allowed) which I plan on cementing my knowledge on during the coming Christmas holidays.
1) 7/9 marks, main point of improvement are
-More past paper questions and improving basic algebra, I lost 2 marks becasue I used P to find the equation of the line through Q and R.
Strengths were being able to determine the centre and radius of the circles.
Strengths were accurately finding the equation of the circle given two points. More work may be needed on this though.
4)5/7 lost two marks( B1) for not finding the gradient of the two equations in order to find the angle between two lines
5) 1/3 for this i need improvement on finding the equations of circles from being given their centre, still don't fully understand but may be because im tired while doing this.
6)1/6 More practice on finding the equation of tangents to the circle at the point A
7)6/8 I lost one method mark and an answer mark because I could not find the value of k for which the line l passes through the origin I made the mistake of not noting down the origin as (0,0).
will edit in the rest tomorrow
Today was a heavy day, mainly biology and chemistry. I wanted to have a really firm grip on the topics which resulted in me going overboard. Do you guys have any tips for structured revision ? because when I limit myself to 1 hour 30 mins or 2 hours I feel like I don't get a lot of work done.
Chemistry 18:10-23:10 ( with short breaks in-between)
I focussed mainly on going through class notes on the "Bonding topic overall". I went through Covalent, Ionic, Metallic and dative bonding and touched upon Shapes of molecules which we haven't learned yet. My weak area is key-terms and I tried to strengthen that part today by memorising and understanding terms such as "Dative bonding - When a covalently bonded compound has one pair or more of lone pair electrons which are donated from one atom" - may need more work.
What I achieved today
-Firm understanding of properties of different types of bonding
-What Giant lattice means (lattice meaning a regular shape and giant meaning it has been repeated in over and over again to form a macromolecular structure).
- Background info that shows why ionic compounds occur and how.
-Made notes on recent lessons
-Understood electronegativity( the relative ability of an atom to attract a and hold electrons in a bond)
Still much work to be done though.
started around 1pm today and finished at 3pm. My main work was on the cell/ plasma membrane and refreshing my memory on that topic. I used boundless to revise and the connections between biology and chemistry became more apparent e.g the polar hydrophobic tails and macromolecules can also be found in the bonding topic. This made things flow more smoothly. I used information to further develop my powerpoint for Biology AS ( I can send it if you want to review it and critique ?) which ill use for revision later.
-The main components of the phospholipid bilayer
-Carbohydrate polymers binding to either lipids or proteins to form Glycolipid or Glycoproteins.
-How the glycolipids and glycoproteins can be used as cell receptor sites for hormones and drugs and also how they are involved in the immune system
-How heat affects the cell membrane by giving the phospholipids kinetic energy to move and become unstable
-How steroid cholesterol strengthens membrane and can protect it against the heat as it make the membrane more stable
-How intrinsic channel proteins transport things that are either too large for the lipid part of the membrane or too hydrophilic.
overall i found the topic a lot to take in and remember some aspects I understood, but more application is needed.
Found a website called a-level notes which also helped further my understanding.
Today I focused heavily on maths since it is my weakest subject, I went over the first half of C1 which included:
I don't really like only doing one subject for a large amount of time a day, but this time I think it was necessary as I had caught up with most of the work in my other subjects. My main plan is to finish the whole of core 1 then move on to smashing out past papers whilst also learning C2 in class. Main sources today were exam-solutions, I used his videos to explain concepts that I got a little confused by. I realised that not having a firm grasp on the basics of c1 resulted in my weaknesses in exams :/
I'm pretty shook by the fact that my AS-level exams are in 7 months
Hello again student room. So its a day into the official holidays and I've completed revision over the past 3 days but no properly coordinated ones. At least not enough to post a log on so I'll summarise them in this starting paragraph then mention the work I did today( including work experience).
7:30-8:30 1 hour
Today for chemistry I revised from a CGP AQA textbook, the information is now becoming easier to understand. I focussed on the areas of different models of the atomic structure, beginning with John Dalton who described the atom as a solid sphere and also said different spheres make up different elements. Then I went on to J.J Thomson who proposed the idea that the atom was like a plum pudding, after the discovery of the electron. The electrons were the plums stuck in the positively charged "pudding" .
Then read up on Rutherford and Geigers gold foil experiment which disproved the plum pudding theory to Niels bohr who proposed the electrons of an atom exist in fixed shells or orbitals of fixed energy and that when electrons moved between shells electromagnetic radiation is emitted or absorbed. Bohr used fitted experimental observation of radiation emitted and absorbed by atoms.
I shifted my focus onto ionisation which I initially found difficult in school; however outside I used websites such as docbrown to further understand the structure of electron shells and orbitals which helped my understanding of the topic. I cemented into my mind the three factors which affect ionisation energy and why( Nuclear charge, Distance from the nucleus, and Shielding from other electrons). Finally, I revived the titration method and equipment involved e.g the indicators that could be used to determine what a solution was: phenolphthalein( which is pink/purple in alkali and colourless in acid) and methyl orange( which is yellow in acid and red/ orange in alkali).
My objectives for chemistry during the holidays are:
-Refresh my knowledge on the chemistry done so far :
Unit 1: Section: 1 Atomic Structure, Section 2 Amount of substance and Section three Bonding
This all includes: Ionisation energy, Titration, Bonding, Nomenclature, Isomerism and Mass spectrometry.
I need to especially revise mass spectrometry as I did not understand graphs which explain that mass spectrum is a mass/charge plotted against abundance. I understood how to work out the relative atomic mass from the spectrum. But did not really understand what the data was showing me.
- Complete homework as well as self marked past paper tests
16:56-19:56 2 hours
For this revision session I used my CGP As-level maths book(AQA) to help me as I did some exam questions. The main focus was Simultaneous Equations and Inequalities in Core 1. My main point of struggle was being confused as to how to place the inequality sign when the question is looking for two values which need to be either bigger than x or smaller than x, respectively, to make the graph positive. But overall the session helped me understand C1. The main objective was to revise part of C1 ( So far I have revised Algebra Fundamentals, Quadratics and Simultaneous equations & inequalities) I have yet to revise ( More polynomials, coordinate geometry, differentiation or integration).
So I am halfway through revising C1 . I did questions on solving inequalities through the use of simultaneous equations. I worked through the booklet slowly but made progress. I intend to revise the rest of C1 then continue practising and slowly going over parts I don't get. I realised that many different parts of C1 ( like finding the discriminant b^2-4ac) can be transferred into other topics and questions which is mainly what confuses me when dealing with more complicated questions. I found that I'm more confident in doing simultaneous equations within inequalities, I also revised how two points of intersection are represented by 2 pairs of solutions to the quadratic, one point of intersection is represented by 1 solution to the quadratic, and how no solutions mean that the graphs do not meet. The line never touches the curve. It is also useful to sketch out the graph in question. To find the range of values for x in an inequality sketch the graph out then use the inequality sign in the question to find the values of x. (e.g if the sign in the question is >) then the answer should be greater than zero (positive).
My main objectives for the two week holidays are to:
- Complete all of C1 which includes: Algebra Fundamentals, Quadratics, Simultaneous Equations and Inequalities, More polynomials, Coordinate Geometry, Differentiation andIntegration.
21:00-23:00 2 hours
In biology today I started off by doing some past paper homework questions on the digestive system mainly
9:00-10:00 am 1 hour
Today I revised mass spectrometry from my chemistry aqa cgp book. I now understand the process of mass spectrometry and how it can be used to determine the relative molecular/formula and isotopic mass of an element. Reading over the book made it simpler, no confusion over that topic any more. I've finished section 1 and all I need now to finish section 2 is to revise the Yield and atom economy. The next weakness I intend to eliminate is my struggle with calculations in chemistry. No real exam questions done besides those in the book. Right now Im trying to understand the content.
Maths - Mechanics 1
11:00-14:00 around 3 hours with a 10 min break inbetween.
For the first time this holiday I practised some SUVAT questions. (S=Distance , U= initial velocity, V=final velocity, A= acceleration and T=Time). At school we have finished Section 1 kinematics which I could still do some work on and have finished Section 2: Statics and Forces . My plan is to go through and understand the concept behind both sections while also applying my knowledge to the questions. Things I did well in:
-Calculating the speed, distance and time using SUVAT equations
- Finding the total speed, distance and time
-Finding the average speed in a question
-I did well on question 4) on show that the speed of the sprinter was 8 after being give the information that the sprinter ran 10 m in 2.5 seconds.
What I found difficult:
- I didn't understand when to apply the SUVAT equations at some questions. E.g when asked to find the speed, I tried using the rather than the actual SUVAT equations which caused me to get the wrong answer.
- I didn't understand how to draw a speed time graph which went below zero on the y-axis.
-I couldn't figure out how to find the time for when a car is decelerating.
This was part of my holiday Mechanics homework which I was overall confident with. I plan on working more on the kinematics section.
My objectives for this holiday in mechanics are to learn the different SUVAT equations:
17:00 - 22:24- Roughly 5 hours around 20 minute breaks inbetween.
Will update section tomorrow and the other one
Recap over the last month. I finally got into the OCRE program at my school for medicine and should be starting meetings new week, haven't been updating the blog because I tried to amp up the revision and now I end up sleeping at around 11:30pm or 12am so I end up being fairly tired. But from now I should be able to properly manage it.
-Involved in a debate club for students( high school to uni) based at the local university
-Going to be presenting the motion for a discussion/debate on 25 February as part of a poetry club I enjoy going to
- Started OCRE and am applying to summer school programs.
Recap on subject
Recently got my results back from a test on C1 Differentiation and Integration. I revised for it mainly by tackling exam solutions, lunch workshops, mymaths( which helped a lot) and MathsandPhysicsTutor. So I have identified which sources I best revise from. On the test I got 52/60 which is 86% and an A grade which I was happy with. However for the university I want to apply to they focus on high ums grades. Many applicants often apply with 90 + ums however I am still happy with the progress I have made. Today for maths I practised an AQA C1 specimen paper for the upcoming mock exams in February. I found most of it straight forward, but I did struggle with:
-Stating the transformations of graphs
-Sketching certain curves
-I need more practise on circles questions and inequality questions.
I also did a 2005 past paper for AQA C1 maths, I marked harshly and got 57/75 which is a B grade. It shows improvement from my initial grades which I like but I am still aiming for high A's. In the test the problems Identified above arose and I struggle with them. ESPECIALLY transformations. For this Intend to visit mymaths.co.uk for an explanation and questions and maths and physics tutor for questions.
I'm genuinely very impressed that you're able to identify what went well, what you could improve, what your goals are for the week and how you're going to meet them
So today was the day we got our mock results back and it wasn't a complete disaster, but still was no where near the grades I was hoping for but before. I will recap on what I have been doing before mocks and after. Mainly heavy revision before mocks, my biggest let down was the fact that I did minimal past paper questions in Biology and Maths. Whereas in Chemistry and Philosophy, they were pretty much my main method of revision. To help my personal statement but more so for a learning experience. I managed to produce a presentation on the effects of the Zika virus with a partner from the OCRE group I mentioned in the original post. I have also visited a university taster day which cemented my application to a particular uni. Then I brushed up an essay I started (only 800 words in) and sent it to a Doctor I was shadowing to assess and read through. I settled on a topic for My EPQ if it is not to late to do one which is
"Will antibiotic resistance ultimately create a stronger healthcare system or will it launch back us into the dark ages of medicine ?"
Chemistry - 47/54which is 87% a grade I was happy with, however disappointed as I still haven't achieved the 92% + above mark.
Religious Studies - 29/35 which is 83 %, unhappy with for the same reasons as above.
Maths - Same as before my weakest point is vectors in mechanics which I have already mentioned.
Actual Mock Grades
Religious studies -A 31/35 on one paper then 28/35 on another
-Was fairly happy with the grade however my teacher told me the points I could have improved on greatly where detail, which I fet myself within the exam. I plan on solving this through more past paper questions and deeper understanding. The question which I choose "Explain the moral issues surrounding Euthanasia", saved me as I learn from previous mistakes and talked about the actual issues rather than Ideas for and against it.
- Was slighlty suprised as I thought I had done better in the Maths and Biology papers than Chemistry. I prepared for the maths questions on the paper which required some substitution and did well on them. However I did not do well on question 3 a, which required you to explain how to carry out a back titration, only scoring 3 marks out of the total 8. During the exam I neglected a loose piece of exam paper and only realised that I did that at the end this cost me 7 marks and the question was on nomenclature.
Maths- C -56/75
During the exam I felt good about my subject knowledge but knew that I had made many mistakes which I would pay for.
In question 1). I got 7 out of 8 marks. Losing one answer mark due to my addition being wrong.
On questions 2). Which was a surds questions I recieved 5/5 marks
On question 3) On integration I got 9/11 marks. I lost two marks because I made a crucial mistake in writing the trapezium area.
I used :
1/2 * (a*b)h rather than 1/2*(a+b)h
For question 4 on circles I gained 10/10.
On question 5(a) for completing the square I received 4/8 marks losing 3 marks for being unable to find an equation using vectors and not being able to state the symmetry of the curveI plan to solve this through more revision as I seemed to have trouble with translations in past papers aswell.On question 6) I got 5/11 marks on differentiation, not remembering the formula for the area of a cylinder. When dividing 48 by 16 I did not cancel out the pi.On question 7 I got 8/12. Marks were lost for not using quadratic formula and trying to factorise.On question 8 I got 7/8. Losing one answer mark for not placing the < sign into the equation.Biology-C
Today I mainly focused on M1 which was homework and slight extra work to do with resolving forces on a slope with and without friction. It took a little bit of practice but with time I eventually began to understand how to draw out the models. A main problem I had was lack of confidence in my diagrams, but that was due to not fully understanding the topic. Mainly the slope model. I did a few questions mainly had trouble with finding the greatest tension and least tension. I printed out 2 M1 past papers (Bronze and Gold) which are arranged in level of difficulty and plan to do them.
At the moment I am comfortable with the pulleys we are learning about and understand how to resolve for tension and acceleration and when the peg is on a slop. Its starting to click I think. memorised equations:
-mgsin - Fr = ma
-mgsin=Fr ( when stationary)
-mgcos= R on perpendicular plane
-mgsin= ma on smooth surfaces.
Then I attended a workshop to complete some C2 work on trigonometric functions and identities, we have recently started the Arithmetic series and nth term, which I found straight forward once I also learned the identities. e.g sin^2x + cos^2x = 1, this helped a great deal in questions which needed me to work out the answer in terms of just sin or just cos. Overall I find C2 much better than I found C1 at the beginning, I think this is because I'm taking a different approach( asking more questions, more confidence in workings)
Note to self: it better to be wrong in class now than in May. Which encouraged me to ask my teacher more about specific questions e.g the greatest and least tensions which helped me discover a new method. Of drawing the simplest model with no friction to produce the basic equations for the directions of forces, then adding in the Fr and other forces afterwards.
Finally today at home, I have been averaging out on C1 papers, (will post more in depth analysis later) 64/75 +, which is low for my targets but is a start. I tried a C1 edexcel Gold paper and was surprised when I saw AQA C2 stuff on it, but managed to handle it still. I found some aspects challenging but my main problem was working with asymptotes - will work on more.
Good websites for maths I used today:
Bronze, Silver and Gold papers
Recently we have started the topic of plant cell structures e.g chloroplasts and their function. However before this I went through the circulatory system in class. I changed up my style, instead of reading information and memorising it I would do past papers and look up the mark scheme instead. I printed and heart and circulatory system from here alevelbiology then completed the questions.
My revision has consisted of reading about the blood vessels through out the body such as the superior vena cava which receives blood from the top of the body, the inferior vena cava which receives blood from the bottom of the body, the pulmonary vein which receives oxygenated blood from the lungs then transports it to the left atrium and then into the left ventricle through the left atrio- ventricular valves. The pulmonary artery the takes oxygenated blood and transports it to the lungs( a gas exchange surface) so that they can be oxygenated). Then finally the Aorta, the biggest vessel on the heart which pumps blood at an extremely high speed and pressure so that it can reach all parts of the organism. The forceful contraction of the thick muscular walls of the left ventricle cause this high pressure.
Circulatory system end of topic questions: 54/69 78% B
Lost 1 mark on 1(a) (ii) which asked to use a table to calculate the contraction time at a heart rate of 60 beats per minute.
Then went on to lose 1 mark on a 6 marker extended writing question on how the structures of the walls of the arteries, veins and capillaries are related to their functions. points I mentioned:
-The muscle layer contracts and relaxes to cause the constriction and dilation of the lumen, which allows the arteries to control the flow of blood
-Elastic recoil maintains high and smooth pressure surges caused by heart beats. The endothelial walls are smooth and reduce friction which my occur when the blood is flowing ( this layer is contained in all of the vessels).
-Small diameter of the capillaries and the one cell thick membrane which provides a shorter diffusion pathway for metabolic materials such as oxygen glucose and water.
The mark I lost was for not mentioning how veins have thin walls as they do not have to withstand high pressures, meaning they are at no risk of bursting.
Another mark lost on question 1 (b), which asked why a pulse can be felt when fingers are placed over and artery that is close to the surface. Explain why a pulse cannot be felt when fingers are placed over a vein which is close to the surface.
- I put the vein carries blood at a lower pressure towards the heart its surges cannot be felt as easily.
This was a biological error- What I should have put was that pressure is constant/smooth in veins and can only have pressure surges in veins.
Further work done.
Went through oxygen dissociation curves which we recently covered to make sure that I thouroughly understood that the side the curve favoured was determined by the oxygen affinity of its haemoglobin. If the oxygen dissociation cure is further to the right, this means that the haemoglobin has a low oxygen affinity, it loads/ associates/combines/ becomes saturated with oxygen less easily and dissociates with the oxygen easily. This type of haemoglobin normally is found in areas of low oxygen partial pressures such as respiring muscle tissue which need more oxygen on demand.
If however the oxygen dissociation curve leaned more to the left, it is haemoglobin with a higher affinity for oxygen. This haemoglobin is found in areas of high partial pressures of oxygen, it associates with oxygen more easily meaning the oxygen saturation levels are high. When carbon dioxide released by aerobic respiration dissolves in the blood to form carbonic acid the ph lowers changing the concentration of the blood and ultimately altering the shape of the protein haemoglobin, causing it to go from a high affinity for oxygen to a low affinity for oxygen, the curve shifts downwards to the right which is called the Bohr effect.
And finally I plan on updating the study blog during the weekend about:
- Questions on Immunity I will be completing from the website(
-Topic 10, plants review, on the chloroplasts and their structures( thylakoids, granum, starch granules, lipid droplets, inner membrane , outer membrane, DNA, free ribosome, membrane bound ribosome's, Stroma and the photosynthetic pigment chlorophyll) and how these structures aid the plant in photosynthesis.
For maths I completed a few more C1 past papers,
C1 Maths may 2013 (67/75) (89%) A
C1 Maths paper (67/75) (89%) A
Finding that I understand many of the topics in C1, my aim is an average of 72 + on the papers before I focus all of my energy onto C2 and M1. I started the week being revising binomial expansion as I did not understand the topic at first, so instead I memorised pascals triangle, and the N choose R rule to help me through the class questions. I worked through my homework of trigonometry identities which I am beginning to understand.
A question that I didn't get was finding the maximum value of f() and stating the smallest positive value of that gives this maximum value. Through use of the graph of sin, I realised that the limits were 1 and -1 therefore we could treat as 1 the maximum positive and 5*1+3 would = 8. meaning theta has to be 90 degrees.
More Binomial expansion
Sequences and Series started: Geometric sequences, arithmetic sequence and the nth term. I am comfortable with the nth term but still struggle slightly with geometric sequences involving finding the sum with out the final term. What confused me was taking away the number at the bottom of the sigma notation from the top then adding one to find the number of terms, alone I understand this, however. This isn't done with other questions and I can still get an accurate answer. I will look into this in workshops but if anyone on the forum could explain it to me I would be grateful.
I then moved onto M1 work, I used exam solutions to help go through the vectors
Today I started off with some biology revision at 8:45, mostly recapping the plants structures and functions , and some summary questions on the counter-concurrent flow in fish. This is when the gill lamellae found in the gill filaments of the fish have blood within them which flows opposite to the direction of the water above in order to keep a steep concentration gradient along the length of the whole lamellae. I plan on going through the question booklet on immunity as it is my weakest topic in biology so far. Then finishing it before I got to bed.
11:15 to 13:15 Mechanics 1
My main method of revision so far has been working on past papers, our class has yet to learn projectiles which I struggled with but I have grasped the concept of vectors, and how to find the time and speed from them. Which used to be my weaker area. Then I went through exam solutions for help on Lift questions, we have done particles on a pulley and on a rough inclined slope repeatedly in class so I am comfortable with them, Now my main task will be to complete an M1 edexcel gold past paper( my exam board is AQA) then report back. Then do some Chemistry Energetics questions along with halogenoalkanes questions.
Finished an M1 G4 gold paper, I found the test quite difficult. However I found that my strong suits lie mainly in suvat equations, for example the first question in the paper.
> Questions 2 a) and b) I found fairly straight forward, a question on calculating the tension in the rope of a lifts questions and the magnitude of the force exerted on the woman by the actual lift.
I worked out the first part by noting the the tension subtracted from the combined weight of the woman and lift = the mass x acceleration or 1000g-T=1000(-2). I tried this question previously and forgetting that deceleration gave a negative number cause me to lose marks.
>Question 3 a) at first I did not understand how to find the angle between F2 or (pi+2pj) and J but, through drawing a diagram of the positive integers p, I knew that they were going North and east respectively. Which allowed me to draw a triangle and use tan theta = 1/2 to get the angle 26.56 or 26.6.
b) After checking my notes I figure out that parallel to I meant that J was =0 therefore the (-3+2p) = 0, when solving this p = 3/2 .
>Question 4 a) and b) I lost marks for not being able to use the impulse ( 7mu / 2) to find the velocities of A and B.
What I needed to do was -I = the Velocity of A - x the speed of A all multiplied by the mas 2m. understanding that 7mu/2 was the impulse allowed my to use - 7mu/2 = 2m( the velocity of A - its speed). Through rearranging e.g multiplying both sides by by 1/2 m then adding 2U to - 7U/2 after cancelling out the masses I got. U/4 then U/2 for the speed of B, the reason why the impulse is not negative and why I did (velocity of b - - 3U) was because particle B was travelling in the opposite direction. This was done during corrections.
a- Dropped marks for being able to label all the forces correctly but not use them properly. what I should have gotten was 49costheta= 6g sin(30), then costheta + 6g sin(30) /49 which gives the anser cos theta = 3/5
b) corrections made were mg costheta + 49 sin theta rather than just mgcostheta alone.
I understood that splitting the angle between P and Q gave me the resultant force, then drawing further line to indicate 15sin(30) and R sin(30). I got the 30 degree angle from the question telling me that the angle between Q and R is 50 and used the fact that it is on a straight line and that the other angle is 100 degrees, to deduce the angle between as being 30 between P and the x axis.
-a) went well understood that because the particle was not moving,Rsin(50)= 15sin(30).
Focussed on preparing for a test on gas exchange, specifically fish and mammals. This was mainly a note taking session, in which I finished the topic of fish and am now going to move onto the gas exchange which occurs in the lungs. Went through expiration and inspiration of fish which I was sure about at first but now understand that during inspiration ( similar to when humans breath in) the mouth opens and the pharynx or the roof of mouth cavity drops, this cause the volume within the mouth of the fish to increase and pressure to decrease which allows the entrance of water. During expiration the mouth closes , the mouth cavity is raised causing the pressure within to increase and the volume to decreasing forcing out the water through the gills and through the operculum valves.
I will go through the mock exam paper at 10:30pm and make any corrections then update.
Chemistry- I worked through a few hess' law questions which required cycles, again I felt rocky going into the revision session, but came out strong; this gives me motivation to continue. Likewise with my mechanics. During the chemistry revision on a free period I manage to do an 1 hour's worth of hess' law questions.
Then more chemistry work was done at home on oxidation numbers and hess' law cycle including a question that gave you the enthalpy of formations of four different compounds and asked you to find the enthalpy change of reaction:
2Al(s) + 3 Cl2(g) -------->2AlCl3(s)
using the enthalpies of formation:
-2Al+6HCl(aq) ------->2AlCl3(aq) + 3H2 ------ -1049.kj/mol
-HCl(g) -----> HCl(g)------------------------------- -74.8 kJ/mol
-H2 (g) + Cl2(g) -----> 2HCl (g) ----------------- -1845.kJ/mol
AlCl3 (s) ------AlCl3(aq)--------------------------- -323.kJ/mol
I needed guidance from a friend inorder to solve this one and realised the you need to have four or more arrows in the cycle
2Al(s) + 3 Cl(g) -------->2AlCl3
\ \ /
\ \ /
2Al + 6HCl (-1049)
\ \ /
0 6HCL 6*(-74.8)
0 3H2+3Cl2 3*(-1845)
The standard enthalpy of formation of elements is zero. Going up the cycle as we are given the enthalpies of formation we get. -0-0+(3*-1845) + ( 6*-74.8) + (-1049)+(2*-323) = -7678.8 or 7679.
In the final 15 minutes I worked on oxidation numbers