physics mcq help needed! urgent!

[halosh92]

O/N 2009
10 14 13 29
20 is maxima n*2?
21 why is it not B??

post the paper plz

[ruby92]

here you go

[ruby92]

12 The diagram shows the masses and velocities of two trolleys about to collide.
-->              --->
2 kg            4 kg
4 m s–1       1 m s–1

After the impact they move off together.
What is the total kinetic energy of the trolleys after the collision?
A1.3J B12J C18J D19J

is it B?

[Phosu]

june 2009 p1 cie
Q10
Q13
explain plz

10) momentum is conserved, take momentum for each side seperately
2m will have speed u
and m will have speed 2u, so that the product of both equations will give 2mu(same momentum)
ke
x= (2u)² y=(u)²
so dividin both will give 4u/u which is 4/1

[Phosu]

is it B?

yah it is B, no worries i figured it out

[ifraha18]

june 2002 q21.

[halosh92]

10) momentum is conserved, take momentum for each side seperately
2m will have speed u
and m will have speed 2u, so that the product of both equations will give 2mu(same momentum)
ke
x= (2u)² y=(u)²
so dividin both will give 4u/u which is 4/1

they didnt mention whether its elastic or non elastic.
and one more question why do they exchange velocities?

[[Spy]]

june 2002 q21.

P is density through out this question.

P=M/V
so V=M/P

the Final Volume =  M/P + M/2P (densities stated in the question)
and this equals 3M/2P

the Final Density i.e P Final is equal to 2M/3M/2P (2M because they are combined together and they have both a mass of M and 3M/2P from the previous step i.e final volume)

therefore, P Final= 4/3 (2/(3/2))

hope its clear

[ifraha18]

oo..thnku..

[[Spy]]

no problem

[ifraha18]

nd q34 jne 2002?

[hesho21]

Plz guys Q no.13 Nov09 posted above  it's a bit confusing

[mz]

may/june 09 questions 15,19 and 29 please asap

please help

[halosh92]

2009 nov Q14
anyone?

[ifraha18]

q 34 and 35 june 2002??