Question

A single 1,300 kg cargo train car is rolling along a train track at 2.0 m/s when 400 kg of coal is dropped vertically into it. What is its velocity right afterward? Assume a closed system. I understand that initial momentum must equal final momentum, which would make the velocity of the coal 6.5 m/s. What I am having difficulty with is determining the final velocity.

1.5 m/s

2.0 m/s

6.5 m/s

0.0011 m/s

Answer 1

WElcome to open study

Answer 2

First find initial momentum

Answer 3

Initial momentum should be 2,600 Kg x m/s since the mass is 1,300 kg and the velocity is 2.0 m/s.

Answer 4

Yep

Answer 5

Now, new mass=1300kg+400kg=1700kg

Answer 6

So, initial momentum=final momentum
2600 = 1700*v
v=1.5m/s

Answer 7

got it?

Answer 8

Ok got it. To get the final velocity it would be initial momentum divided by the new mass. Thanks.

Answer 9

WELcomx