you HAVE to do better if you're resitting in summer don't you O.O :/ because its the last sitting that one counts even if its lower my teacher says :/ ... (AQA )
Highest grades go forwards. Like for my biology coursework.
Same! I hate ray diagrams and electricity and magnets
Magnetism is awesome I didn't really like it until I watched khanacademy's video on it though, things tend to become significantly more awesome when FP3 vectors are chucked in
I like the ray diagrams .. although drawing an optical fibre without a protractor is annoying -.- Yes magnets and electricity ... my hatred runs deep !
I learned spearmans rank correlation coefficient other day expecting it to be hard .... so boring :L (its harder to say the name )
Magnetism is awesome I didn't really like it until I watched khanacademy's video on it though, things tend to become significantly more awesome when FP3 vectors are chucked in
seriously .... now I may be wrong but i'm just repeating his words, so because I know no more I shall withdraw my case
I don't understand how it would make sense seeing as GCSEs can be finished in either year 10 or 11. If you screw up in summer yr11 and you needed it then it would make sense but...
Just had my General and Credit math exams, both the General non-calculator and calculator exams were easy as usual but the Credit non-calculator was surprisingly easy and the calculator exam was alright up until the last question - which I completely gave up on.
Well, this is easier to remember for A-level Physics because you have a simplified version of this formula there, but I'll try to explain it anyway.
F=I(ℓ×B)
This is for a current-carrying wire in a magnetic field.
F is the force on the wire, I is the current, l is the length of the wire, B is the magnetic field strength.
Now, afaik current is neither a scalar nor a vector, so just treat it as a "value". So it doesn't really matter here.
For GCSE and A-level purposes, it is assumed the wire is at right angles to the magnetic field. And for A-level (I don't think this formula is used for GCSE), only the magnitude matters.
So,
F=I(ℓBsin90∘)
sin 90 as they're at right angles.
This simplifies too:
F=BIℓ
This is the standard formula given for A2 Physics.
Now, look at the vector formula. Observe the cross product in the brackets.
Look at the diagram on the page of the FP3 book I gave you.
The diagram of n-hat, a and b.
l can be taken as a here, B can be taken as b, and F would be n-hat.
The angle between l and B (a and b) would obviously be 90 degrees, since as said before, at GCSE/A-level you're only looking at when the wire and magnetic field are at right angles.
Now, l is the length of the wire. The current travels along the length of the wire. So this can be taken as the direction that the current flows in.
So, again, the diagram of a, b and n-hat. n-hat is still F, b is still B. Now, a is I rather than l.
This diagram is basically what "Fleming's left-hand rule" is trying to demonstrate.
I'd recommend watching khanacademy's videos on magnetism if you don't get this. However, they don't say how the left-hand rule is derived (I figured this out on my own ). Watch those and re-read by post and you'll get it for sure (assuming you don't already get it).
Well, this is easier to remember for A-level Physics because you have a simplified version of this formula there, but I'll try to explain it anyway.
F=I(ℓ×B)
This is for a current-carrying wire in a magnetic field.
F is the force on the wire, I is the current, l is the length of the wire, B is the magnetic field strength.
Now, afaik current is neither a scalar nor a vector, so just treat it as a "value". So it doesn't really matter here.
For GCSE and A-level purposes, it is assumed the wire is at right angles to the magnetic field. And for A-level (I don't think this formula is used for GCSE), only the magnitude matters.
So,
F=I(ℓBsin90∘)
sin 90 as they're at right angles.
This simplifies too:
F=BIℓ
This is the standard formula given for A2 Physics.
Now, look at the vector formula. Observe the cross product in the brackets.
Look at the diagram on the page of the FP3 book I gave you.
The diagram of n-hat, a and b.
l can be taken as a here, B can be taken as b, and F would be n-hat.
The angle between l and B (a and b) would obviously be 90 degrees, since as said before, at GCSE/A-level you're only looking at when the wire and magnetic field are at right angles.
Now, l is the length of the wire. The current travels along the length of the wire. So this can be taken as the direction that the current flows in.
So, again, the diagram of a, b and n-hat. n-hat is still F, b is still B. Now, a is I rather than l.
This diagram is basically what "Fleming's left-hand rule" is trying to demonstrate.
I'd recommend watching khanacademy's videos on magnetism if you don't get this. However, they don't say how the left-hand rule is derived (I figured this out on my own ). Watch those and re-read by post and you'll get it for sure (assuming you don't already get it).