Question

A 1.0kg cart moving right at 5.0 m/s on a frictionless track collides and
sticks to a second cart moving left at 2.0 m/s. The two carts have a final
speed of 1.0 m/s to the left.
What is the mass of the second cart?

Answer 1

Let’s use the *queue dramatic voice* LAW OF THE CONSERVATION OF MOMENTUM!
m1v1i + m2v2i = m1vf + m2vf

m1v1i - m1vf = m2vf - m2v2i

m1(v1i - vf) = m2(vf - v2i)

m2 = [m1(v1i - Vf)] / (vf - v2i)

m2 = [(1)(5 - -1)] / (-1 - -2)

m2 = 6 / 1

m2 = 6 kg
And that’s your final answer! Please press “Thanks”!