I thought if the mass increase the volume decreases but since CSA was the same it could only be L decreasing so I drew straight line through origin because I thought M would be proportional to 1/L but really not sure as I panicked

Reply 52

Super199

Original post by sadasdasdasd

M proportional to pressure and L is proportional to volume therefore graph is a straight line through the original.

Thats what i did but i was confused about why it was negative (the y axis)

Reply 53

headyb

Original post by sadasdasdasd

M proportional to pressure and L is proportional to volume therefore graph is a straight line through the original.

That's good to hear.

I don't suppose a figure of around 0.22 kg/s rings a bell for the flow of water concerning the specific heat capacity question?

Reply 54

sadasdasdasd

Original post by adsy9

was that the flow of water?

how did you guys do the flow of water question?
I calculated energy per 1.6 seconds as E = 130*10^3 * 1.6*10^-19 * 5*10^7
This energy multiplied by 0.9 therefore E*0.9=M*(SHC)*deltaT to work out M.
Then used D=M/V to work out volume
Finally this volume divded by 1.6 to give the volume per second.

(edited 6 years ago)

Reply 55

sadasdasdasd

Ask me any questions guys, think I can remember most

Reply 56

mathsmaths2017

Original post by sadasdasdasd

Ask me any questions guys, think I can remember most

unofficial mark scheme please

Reply 57

betasoup

Original post by Super199

Thats what i did but i was confused about why it was negative (the y axis)

I just did it from the Origin because you can't have a negative length but that's why I panicked because I saw it had a negative region but my line didn't go into the negative region

Reply 58

betasoup

what do you reckon the grade boundaries will be ?

Reply 59

sadasdasdasd

Original post by mathsmaths2017

unofficial mark scheme please

dunno exactly what the questions are in order, or the numbers, but can remember the method probably

1) strontium and alpha nucleus
a) velocity of alpha nucleus
energy and mass given therefore 1/2*m*v^2
b) newtons laws to explain motion of strontium
strontium experiences a force as alpha particle experiences a change in momentum?
Repulsion between the two are equal and opposite, also act on each others bodies?
c) calculate v of strontium
M(initial)*v(initial) = M(final)^v(final)

2) ?

3)

4)

5)Thermal physics
a) work out initial n of baloon
use 4/3*pi*r^3 and PV=nRT using initial T, P
b) work out final pressure of baloon before it pops
use 4/3*pi*r^3 for new V and PV=nRT using final T, initial n, final V
c) ratio question
E=3/2KT therefore ratio is T(final)/T(initial)

Help.. pls