ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: cranberry on May 19, 2011, 08:47:14 pm

Title: neap 2009 trial exam question
Post by: cranberry on May 19, 2011, 08:47:14 pm

ive got a few questions wrong, which the solutions don't explain that well...need some help/explanations :laugh:
i can't select text and copy out the q's here so you'll have to see the exam attached :S (sry :() :coolsmiley:

the q's in order of preference are:

Motion
Q5 (i used -F(sum of) = -mg + Fnormal, and got 22461N...
Q14 (used the period formula T = sqr root(((4Pi^2r^3)/GM)) with 3650000 as radius) got secs then min then hrs (div by 60) way off..

S&M
Q 5
Q 13


thanks heaps VN  :angel:

Title: Re: neap 2009 trial exam question
Post by: onur369 on May 19, 2011, 08:55:25 pm

Whats the answer for q 5 ? I got 24600

Title: Re: neap 2009 trial exam question
Post by: cranberry on May 19, 2011, 08:59:52 pm

5640N :(

Title: Re: neap 2009 trial exam question
Post by: onur369 on May 19, 2011, 09:15:59 pm

fnet= mg-n
n=mg-fnet
mg= 300x10
Fnet= mv^2/r = 300x144/5 = 8640

3000-8640 = -5640 N.

Thats the best i got

Title: Re: neap 2009 trial exam question
Post by: MissIraq on May 19, 2011, 09:21:13 pm

hey cranberry where are you getting these trials?

Title: Re: neap 2009 trial exam question
Post by: cranberry on May 19, 2011, 09:22:38 pm

ah okay...cool ty man..
i new that for the minimum speed at the top of the circular path Fnet=mg...so when the object is not travelling at its minmun speed Fnet (at top) = mg + Fn ye? ...neap's solutions aren't clear enough

Title: Re: neap 2009 trial exam question
Post by: onur369 on May 19, 2011, 09:24:18 pm

yes

Title: Re: neap 2009 trial exam question
Post by: cranberry on May 19, 2011, 09:24:48 pm

Quote from: MissIraq on May 19, 2011, 09:21:13 pm

hey cranberry where are you getting these trials?

from our teacher, but im sure they are on VN somewhere...

heres solutions from 2009 if u guys want...