Question

a toy car of mass 0.01 kg, gets into an elastic collision with a toy train mass 0.35 kg. if the train is at rest and the car is moving at 2 m/s initially. how fast is the train moving after the collision? Use the equation ((2*m)/(m+t))*v

Answer 1

Initial momentum = 2 * .01 = .02
= final momentum
= .01 cv + .35 tv
so
cv = 2 - 35 tv

Initial Ke = (1/2)(.01)(4) = .02
= final Ke
= (1/2)(.01) cv^2 + (1/2)(.35) tv^2

4 = cv^2 + 35 tv^2

4 = (2 - 35 tv)^2 + 35 tv^2
4 = 4 - 140 tv + 1225 tv^2 + 35 tv^2
140 tv = 1260 tv^2
tv = 140/1260 = 0.111 m/s