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I also need to revise but so many distractions
Reply 101
A rider rides a motorbike of mass 300kg. He applies the brake and reduces the speed of the motorbike from 18m/s to 3 m/s. Calculate the kinetic energy lost by the motorbike. How would you do this? I got 33750J, anyone got anything different?
Yeah I doubt that question will come up as a 6 marker but I imagine something will come up on it, they seem to like that topic, so best to be prepared :smile:

I hope I'm prepared but I just never know what topics to focus on in the final hour or so of revision - I'm not like some people who seem to revise weeks in advance, I start 1 week before properly and rarely cover everything, leaving out things I understand, which has worked in exams so far but I'm finding it hard to work out what I struggle with for P2! I'm expecting questions on: Nuclear Fission/ Fusion and radiation, momentum, the basic forces stuff and mains electricity - but there's nothing to back what I think will come up, just looking at the past papers and what came up in specimen and last years paper. For example, in one of the other exams in May last year, I ignored a whole topic as it had been in the specimen and last 2 papers and it paid off as it never came up!

My teacher said to expect a lot of equations questions though, not sure how she knows!

Any advice anyone has on conversions? e.g. Kilowatts to Watts - it seems so basic but this is where I always lose marks in equation questions!

Anyway, this evening for final revision I'm going through a booklet we got given, quick look at the specification to check I know it all, make a small summary postcard and then maybe just watch some myGCSEScience videos to finish - much more relaxed than the last minute cramming most of my friends do but I only think that would panic me more!
Original post by syhash
Any ideas about the 6 mark question? :smile:


Car design!!
Original post by lolface32
A rider rides a motorbike of mass 300kg. He applies the brake and reduces the speed of the motorbike from 18m/s to 3 m/s. Calculate the kinetic energy lost by the motorbike. How would you do this? I got 33750J, anyone got anything different?


I got 47250 J because you have to find out the kinetic energy when the speed is 18 and then 3 using the formula : Ek= 1/2 x mass x velocity(squared) and then find out the difference.

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Original post by MajorRisk
Car design!!


The thing is how would that fit into a 6 marker- I can understand 3 marks x feature increases the time taken for the collision to take place reducing the rate of change of momentum and thus reducing the force exerted on a person during a collision and thus preventing injuries and this response would be extremely repetitive for other features but energy changes might have to be included eg.car distortion zones increase the time taken for kinetic energy to convert into heat energy, which occurs when a car crashes as friction is occurs between the tyres and the road as work is done, reducing the chances of fires and thus reducing the chance of injuries.
Reply 107
Original post by pinkgorilla
I got 47250 J because you have to find out the kinetic energy when the speed is 18 and then 3 using the formula : Ek= 1/2 x mass x velocity(squared) and then find out the difference.

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Yeah that's what I done?
I think I am getting the velocity bit wrong :confused: I done 1/2 x 300 x 15^2
Original post by pinkgorilla
I got 47250 J because you have to find out the kinetic energy when the speed is 18 and then 3 using the formula : Ek= 1/2 x mass x velocity(squared) and then find out the difference.

Posted from TSR Mobile


that is correct- I did the change in kinetic energy and messed it up when I did this question but its important to remember that that is done for calculating change in gravitational energy not kinetic energy.
Reply 109
Original post by Dalek1099
The thing is how would that fit into a 6 marker- I can understand 3 marks x feature increases the time taken for the collision to take place reducing the rate of change of momentum and thus reducing the force exerted on a person during a collision and thus preventing injuries and this response would be extremely repetitive for other features but energy changes might have to be included eg.car distortion zones increase the time taken for kinetic energy to convert into heat energy, which occurs when a car crashes as friction is occurs between the tyres and the road as work is done, reducing the chances of fires and thus reducing the chance of injuries.

You could also talk about how force is spread ( in air bags for example) over the upper body for minimal damage!
Original post by lolface32
Yeah that's what I done?
I think I am getting the velocity bit wrong :confused: I done 1/2 x 300 x 15^2


(1/2*300*(18^2))-(1/2*300*(3^2))
Please sugegst your predictions of what the 6marker will be and i will do a poll, electrolysis came 2nd last poll and was in them chem exam, so may as well try it again! :smile:
Reply 112
Original post by Dalek1099
(1/2*300*(18^2))-(1/2*300*(3^2))

aaah! Makes sense, well that was stupid of me!
(edited 11 years ago)
Reply 113
Original post by Mrkingpenguin
Please sugegst your predictions of what the 6marker will be and i will do a poll, electrolysis came 2nd last poll and was in them chem exam, so may as well try it again! :smile:

-Nuclear Fission& Fusion
- Uses of Radiation
- Forces in Action
-Car safety( I doubt it though)
-Stars (Doubt this to)
Something on electricity or the universe I reckon. I'm just assuming this exam is going to be challenging to make sure I don't I get a shock like I did today in Chemistry. Let's hope for lots of maths because that is where my A* is!
Reply 115
Original post by bbadonde2
Something on electricity or the universe I reckon. I'm just assuming this exam is going to be challenging to make sure I don't I get a shock like I did today in Chemistry. Let's hope for lots of maths because that is where my A* is!

Not to much, a little basic theory thrown in would be nice to :biggrin:
Original post by lolface32
Not to much, a little basic theory thrown in would be nice to :biggrin:

Yes but I was a bit disappointed with the amount of maths in Chemistry today. I would like some theory as well other our study would have been pointless!
Reply 117
Here is a little Radiation question!

If one litre of milk contaminated with iodine-131 gives a count rate of 400 counts/second, how long will it take for the count rate to fall to 25 counts/second? Half life of Iodine-131 is 8 DAYS!

Would appreciate if someone asked me a hard question btw!
Original post by Mrkingpenguin
Please sugegst your predictions of what the 6marker will be and i will do a poll, electrolysis came 2nd last poll and was in them chem exam, so may as well try it again! :smile:


I have an inkling on safety and electricity.The question would be How can people protect themselves from electric shocks? and what safety measures exist to help people avoid getting electric shocks?

You could talk about wiring a plug safely,fuses and earth wires, double insulation because people have wet hands when using hairdryer,RCCBs, not handling electric equipment when you have wet hands, that wires are thick and short to prevent warming effects on wire and that wires are made in insulating materials both in the main cable and the wires inside the plug.
Reply 119
Original post by bbadonde2
Yes but I was a bit disappointed with the amount of maths in Chemistry today. I would like some theory as well other our study would have been pointless!

Lol, yeah chemistry theory is the worst. So complicated, I got a A* last year for C2( 92 UMS) but there was not to much of it :biggrin: It will only get harder at A-level!

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