Need help for A level physics p5

[arvin vinz]

Hello guys,
I need help for A level physics paper5 (9702_w11_qp_51) http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w11_qp_51.pdf
I have attempt all question and am stuck on question C (iv) and D (i),(ii) i have look up for the answer on the markscheme but i do not understand how to calculate it..
can anyone can help me with it
Thanks

 

[♣♠ Magnanimous ♣♠]

Hello guys,
I need help for A level physics paper5 (9702_w11_qp_51) http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w11_qp_51.pdf
I have attempt all question and am stuck on question C (iv) and D (i),(ii) i have look up for the answer on the markscheme but i do not understand how to calculate it..
can anyone can help me with it
Thanks

Thought blocker

 

[nehaoscar]

Hello guys,
I need help for A level physics paper5 (9702_w11_qp_51) http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w11_qp_51.pdf
I have attempt all question and am stuck on question C (iv) and D (i),(ii) i have look up for the answer on the markscheme but i do not understand how to calculate it..
can anyone can help me with it
Thanks

Since the graph is plotted of logT agains logr we have to take logs on both sides of the original equation
original equation = T^2 = kr^3
logT^2 = logkr^3
2logT = logk + 3logr
logT = 0.5logk + 1.5logr
comapare this with y = mx + c
y = log T
x = logr
m = 1.5
c = 0.5logk

for part c (iv) you know the gradient and use any point from your graph to find out c by using the comparison given above. (since you know y,x and m)

for part d (i)
you have calculated c
c = 0.5logk
k = 10^(0.5c)

and part d(ii) is just substituting the values calculated to obtain M.

You will need to know logarithms for this paper and the rules of how to apply logs
Hope you understand it now!