VCE Physics Question Thread

oarfi123

Post questions regarding VCE physics here. Enjoy! 😀

God

Heyo, can someone help with this question? It was on an exam (2022 neap) I did and I had no clue how to answer it. (Still waiting for my teacher to mark it)

Two carts connected with a spring accelerate, and the spring snaps at one end - leaving one car going faster than the other.

Q: why is this not considered an elastic or in elastic collision?

I may be remembering this wrong - but How can a collision be neither elastic nor inelastic?

oarfi123

God

An elastic collision is when the kinetic energy before and after, which basically means there is no loss of kinetic energy and its conserved, while in an inelastic collision the kinetic energy before and after are different values*, which means that some kinetic energy has been transformed into some other energy like heat or sound energy.

Regarding your question, as one of the cars is faster than the other this implies that kinetic energy was not conserved thus it becomes an inelastic collision.

Only kinetic energy might no the conserved but the total every is always conserved as per the Law of conservation of Energy

God

oarfi123

Yeah that's why I was so confused. I probably just misread the question (Let's hope anyway).

Presuming I didn't - Perhaps it was because there was no 'collision', just a separation? But that doesn't sound right. Or perhaps the momentum wasn't conserved - and hence testing the K_E becomes meaningless.... Idk.

When I get it back I'll touch base. Hopefully I was just being stupid!

God

Apparently the kinetic energy increased (because the energy stored in the spring was transferred to the carts)

Thus it was neither elastic or inelastic.

God

Also - If anyone else is doing Neap exams and running out of time. U r not alone. 😓
(The 2018 one was sooooo painful)

SnekiSnek

Is it better to handwrite or type the cheat sheet for the exam?

Billzene

SnekiSnek as someone who did biophysics in uni which allows a cheat sheet, definitely handwritten

genius

Hello everyone,

Can someone help me with this physics question?
A water skier at the Moomba Masters competition in Melbourne leaves a ramp at a speed of 50 km h−1 and at an angle of 30°. The edge of the ramp is 1.7 m above the water. Calculate:

a) the range of the jump

b) the velocity at which the jumper hits the water.

The answers on the textbook say 19.6m for part a and 15.0m/s in the direction of 37 degrees below the horizontal for parrt b.

Thanks!!!