Impulse and Momentum?

Question

Three identical train cars, coupled together, are rolling east at 2.0 m/s. A fourth car traveling east at 4.0 m/s catches up with the three and couples to make a four-car train. A moment later, the train cars hit a fifth car that was at rest on the tracks, and it couples to make a five-car train. What is the speed of the five-car train?

Answer 1

I'll give the calculations for the principle given by the first answerer above because I agree with what he said.

Initial momentum of 3-car train=3m*2
Initial momentum of 4th car=m*4

Momentum of 4-car train=4m*v

Based on conservation of momentum:
3m*2+m*4=4m*v m cancels out.
6+4=4v
v=10/4
=2.5m/s This is the speed of the 4 car train.

Therefore, initial momentum of 4-car train=4m*2.5
initial momentum of 5th car=m*0

Momentum of 5-car train=5mv'

Again using the same principle:

4m*2.5+m*0=5mv'
10=5v
v=2m/s.

Answer 2

Impulse The exchange in momentum is named the impulse and is given the physics code Dp. we can outline Newton’s 2d regulation in terms of exchange of momentum: tension = exchange in momentum __________________ term Þ Impulse (Ns) = tension (N) x term (s) In code: Dp = FDt Momentum is the product between mass and velocity. Being a vector volume, it has a course, and the course is quite important whilst doing momentum calculations. Momentum isn't a component that we can see, even though it does clarify many stuff that bypass on in physics. Momentum (kg m/s) = mass (kg) x velocity (m/s) gadgets are kilogram metres according to 2d (kg m/s) or newton seconds (Ns). we can tutor that the gadgets are the comparable.

Answer 3

Conservation of momentum, conservation of momentum

Assum that each car has the same mass as the others.