IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: manuroqs on May 18, 2010, 05:28:57 pm

Title: mechanics help
Post by: manuroqs on May 18, 2010, 05:28:57 pm
hi! the mechanics ppr is tommorrow..Can anybody help me out with a question.It's from OCT/NOV 05 Q7)iii).How do u do it?
Title: Re: mechanics help
Post by: astarmathsandphysics on May 18, 2010, 05:38:59 pm
here
Title: Re: mechanics help
Post by: manuroqs on May 18, 2010, 05:54:05 pm
thanx :)
but the answer is wrong for the last part,it's 3.456 J in the marking scheme.I think u made a mistake in calculating the distance for ball with mass 0.3g
Title: Re: mechanics help
Post by: astarmathsandphysics on May 18, 2010, 05:58:49 pm
Check my working. Home again soon.
Title: Re: mechanics help
Post by: Igcseboy on May 18, 2010, 06:10:30 pm
hi! the mechanics ppr is tommorrow..Can anybody help me out with a question.It's from OCT/NOV 05 Q7)iii).How do u do it?


which board???
Title: Re: mechanics help
Post by: cooldude on May 18, 2010, 06:14:00 pm
thanx :)
but the answer is wrong for the last part,it's 3.456 J in the marking scheme.I think u made a mistake in calculating the distance for ball with mass 0.3g

the height at which A is above the floor is-->
s=t(u+v)/2
s=1.2(0+2.4)/2
s=1.44m
B's final velocity-->
v^2=u^2+2as
v^2=2*2*1.44=2.4 m/s
dist travelled by B after string becomes slack until it comes to rest-->
v^2=u^2+2as
0=2.4^2+(2*-10*s)
s=0.288m
therefore total dist=0.228+1.44=1.728m
gain in gpe--> mgh=0.2*1.728*10=3.456 J
Title: Re: mechanics help
Post by: zioziozio on May 18, 2010, 06:25:23 pm
hey guys .. can you please tell me the hardest mechanics paper u've solved before .. ?
because am revising and i need to know how the hard questions come .. Thanks :)
good luck to all !! :)
Title: Re: mechanics help
Post by: AL*Eagle on May 18, 2010, 08:56:27 pm
hi! the mechanics ppr is tommorrow..Can anybody help me out with a question.It's from OCT/NOV 05 Q7)iii).How do u do it?

edexcel or cambridge??
Title: Re: mechanics help
Post by: manuroqs on May 19, 2010, 08:14:36 am
cambridge.But COOLDUDE solved it ;D