Questions 15-17 Mid-Year 2010!!!

[a.zirek]

I thought of it like this...
In an inelastic collision, we have Ek transferred to heat,sound energy and the total energy after the collision is less than the initial. BUT, the momentum is still the same.

Sooo.... if we were to have some of the energy momentarily transferred to the spring, wouldn't we still have the same momentum?

[KRISTOFFA]

Omg... momentum is ALWAYS conserved.
/facepalm

[Killerkob]

Momentum should be conserved no matter what in that kind of situation. So ABB

i agree but wtf happens to the momentum whilst the spring compresses?

It was a frictionless table, so it's not as if the spring had to 'build up energy' in order to push the other block as it got scrunched up. It's the contrary, actually, as soon as the spring even bumps the second block, that second block goes flying away. So during the whole experiment, momentum was smoothly transferred, with a constant total amount.

[tha1ne]

i got B,B,B -  i just don't get y the teachers still think the answers are AAA


( ey and anil, btw the guys on itute think its A,B,B aswell. so i think maybe arif failed)

[John President]

It said momentum not kinetic energy. I had C initally aswell.

Oh bugger. Thought I had got full marks.

[a.zirek]

Oh that sucks.
I just found out that I did got full marks.

[John President]

Oh that sucks.
I just found out that I did got full marks.

Well done!

Guess I learnt a valuable lesson - The question will not always be what you're expecting it to be.