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

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: yinyang on May 15, 2010, 07:48:58 pm

Title: physics help needed
Post by: yinyang on May 15, 2010, 07:48:58 pm
Can anyone please solve these two questions

june 2009
Q 14
Q 15
 ??? ???
Title: Re: physics help needed
Post by: T.Q on May 15, 2010, 07:58:59 pm
edexcel or cie

and which paper ??
Title: Re: physics help needed
Post by: yinyang on May 15, 2010, 08:02:49 pm
it's cie  paper 1 sorry for not mentioning earlier  :D
Title: Re: physics help needed
Post by: astarmathsandphysics on May 15, 2010, 08:39:29 pm
Will try when i get home
Title: Re: physics help needed
Post by: astarmathsandphysics on May 15, 2010, 10:39:09 pm
14. P=Fv
F=kv^2 so P=kv^3 C
15 the water in the top half may be considered to go into vessel Y, falling average height h/2 in the process so loss of GPE=mgh/2 C
1
Title: Re: physics help needed
Post by: yinyang on May 16, 2010, 11:16:14 am
that's what i thought for Q15 but according to the marking scheme the answer is B(mgh/4)???
Title: Re: physics help needed
Post by: cashem'up on May 16, 2010, 12:09:34 pm
hey june 2007 q20......dont get it please explain....... by the way cie.....Thanks
 ;)
Title: Re: physics help needed
Post by: cashem'up on May 16, 2010, 12:17:03 pm
of the same paper can someone also explain why in q27 the answer is A not B......why do the directions  have to be different is it because of the original wave and the reflected wave???  :(
Title: Re: physics help needed
Post by: astarmathsandphysics on May 16, 2010, 12:40:11 pm
Think ms may be wrong on q15
Title: Re: physics help needed
Post by: hetarth on May 16, 2010, 12:50:21 pm
ok kk listen up when the weight  pulls the beam downwards the side at which x and y lie on have been stretched so tension applies there .....so answer is b
Title: Re: physics help needed
Post by: cashem'up on May 16, 2010, 01:26:26 pm
Quote from: hetarth on May 16, 2010, 12:50:21 pm
ok kk listen up when the weight  pulls the beam downwards the side at which x and y lie on have been stretched so tension applies there .....so answer is b

can u be more specific in terms of moments or etc....
Title: Re: physics help needed
Post by: cashem'up on May 16, 2010, 03:13:41 pm
Quote from: ima_shah2002 on May 16, 2010, 12:09:34 pm
hey june 2007 q20......dont get it please explain....... by the way cie.....Thanks
 ;)


astarmathsandphysics...........sir can  u please help me out wid these questions.....Thanks
Title: Re: physics help needed
Post by: halosh92 on May 16, 2010, 03:17:37 pm
june 2009 p1 cie
Q10
Q13
explain plz
Title: Re: physics help needed
Post by: astarmathsandphysics on May 16, 2010, 07:44:38 pm
10 from conservation of momentum speed of X is twice speed of Y since mass of X is half mass of Y
do (1/2 m (2v)^2)/(1/2 2m b^") =2
13 moments about spindle 0.2*900 =9.6F so F=300
Title: Re: physics help needed
Post by: halosh92 on May 16, 2010, 07:52:42 pm
Quote from: astarmathsandphysics on May 16, 2010, 07:44:38 pm
10 from conservation of momentum speed of X is twice speed of Y since mass of X is half mass of Y
do (1/2 m (2v)^2)/(1/2 2m b^") =2
13 moments about spindle 0.2*900 =9.6F so F=300

thankyou but Q13: answer is 150N