Question

Railroad car A, with mass 6275 kg, is traveling east at 6.5 m/s along a straight track. It strikes railroad car B, with mass 5155 kg, which is also traveling east along the same track at 3.8 m/s. The two railroad cars stick together. Assume the track is frictionless.
How Fast do the two attached railroad cars move immediately after the collision?

Answer 1

The speed of A and B immediately after collision is 5.28m/s

Explanation:

Mass of A is 6275kg

Speed of A is 6.5m/s

Mass of B is 5155kg

Speed of B is 3.8m/s

Track is frictionless.

A and B stick together.

speed of attached A and B = ?

mₐsₐ + mᵇsᵇ = (mₐ + mb) s

$6275 X 6.5 + 5155 X 3.8 = ( 6275 + 5155) X s\\\\s = \frac{40787.5 + 19589}{11430}\\ \\s = \frac{60376.5}{11430}\\ \\s = 5.28m/s$

Therefore, The speed of A and B immediately after collision is 5.28m/s