Official OCR A G481 mechanics 20th May 2013

I did b-a (because they were acting in opposite directions )to find the net force and then used F=ma so a= F/m.. If we are talking about the same question

raw mark for 90ums is always 60/60. has anyone got the paper can you please email it to me..

Do you know for the terminal velocity question is it ok if i said weight = upthrust ?

No, not always. Look at this thread about the N grade.
http://www.thestudentroom.co.uk/showthread.php?t=649874

Also here is the poll: http://www.thestudentroom.co.uk/showthread.php?t=2357507

i remember some answers but not the actual questions they were answering :P , so ill just post random answers i got



kgm^-2
giga is 1000 times bigger than mega
density = 1.6x10^-? kgm-3 [forgot what it was to the power of]
force constant is the force per unit extension
R=1.4x10^-5 and F=6.3x10^-5 (something close to these)

3.5ms^-2 for instantaneous acceleration of a trolley i think
I got ratio of B/A as 2.8N
the moments question i got x(50-x)=12x and i think the answer was 0.37m

the question about power:
-power is rate at which work is done
-work done = 5.4x10^?
-output was 390 Watts
-Input was 1228 Watts / 1.3x10^3 Watts

i wrote for one question something about weight being smaller than drag at t=0.05 because the ball was decelerating and then at t=0.25 they were equal/there was zero acceleration

for the Youngs modulus question i got 1.9x10^9 Pa

For the last question i wrote that it was polymeric but forgot to finish my explanation of why it was good for aeroplane tyres (doh!) :L

i basically fluffed my way through the explanations; dont think i did that well tbh :L did anyone get similar answers to me?

For the component question ( I think it was Q2 or Q3 ) I didn't actually calculate it.

I wrote 5sin30, and 13cos30 ( I made up the numbers, can't remember the actual numbers)

Is that right or did u have to calculate it

What did people get for the question with the Force (R) and Force (F) of the water droplet on the window. (8.0*10-5N)

i put 1.6 or something then scribbled it out and put 4.2 or something

i did youre trolley one was the same as mine