Edexcel IGCSE Physics 20th May 2015 discussion

I put the ray inbetween yellow and blue

I left that question to last and I suddenly remembered i had to still do it when I had like 2 mins left so i just yolo`d it and I messed up

Oh well, its only 1 mark

Hey what did people put for the knee pad question, i thought it was to do with increasing area to reduce pressure but other people said it was to do with newton's second law

I related it to an air bag in a car. I said it reduces the time it takes for the girl to stop so it therefore increases change it momentum and decreases time and I related it to the formula force = change in momentum / time. So the girl experiences less force and therefore less injuries occurs

did you put that due to the pressure decreasing the flow decreases p=dgh?

Actually it was 2...

I related it to an air bag in a car. I said it reduces the time it takes for the girl to stop so it therefore increases change it momentum and decreases time and I related it to the formula force = change in momentum / time. So the girl experiences less force and therefore less injuries occurs

Yep I did put that, I actually had a feeling I don't know what inversely proportional graphs look like, so I wrote loads in case I was wrong somewhere. I feel so stupid right now, I thought I was good at maths and I actually had revised these graphs a lot for the maths exams argh! I hope they weren't specifically looking for 'inversely proportion' for the second mark.

I said the graph was exponentially decreasing in terms of the x and y things, because in the textbook it had a very similar graph but for the decay of radaiton sort of stuff, and it followed literally exactly the same shape as the graph in the exam. I also included values and i added loads of explaination to back up my point cause I wasnt sure if my first point would be considered valid :/

I think you had to say:
1) The depth decreased as time increased
2) It was a non-linear relationship

I have seen past papers and they are the two points they usually want you to give but they usually have some other stuff in the 'accept' such as negative gradient.

How does it increase change in momentum?

Other than that, we have exactly the same answers

EDIT - Actually, wouldnt the soft knee pads increase the time taken to stop? Because they compress slowly like the airbags in cars?

I think you had to say:
1) The depth decreased as time increased
2) It was a non-linear relationship

I have seen past papers and they are the two points they usually want you to give but they usually have some other stuff in the 'accept' such as negative gradient.

Sorry Yeh it was the other way around it increases time but decreses change in momentum. That's what I wrote ite in the exam
😝

Does any one remember how they calculated the answer for the last question? Method wise.

Does any one remember how they calculated the answer for the last question? Method wise.

are you doing edexcel iGCSE history?