A 14,000-kg boxcar is coasting at 1.50 m/s along a horizontal track when it suddenly hits and couples with a stationary 10,000-kg boxcar. What is the speed of the cars just after the collision?

Explanation:

It is given that,

Mass of a box car,

Initial speed of a box car,

Initial speed of another stationary car is 0 as it was stationary

Mass of another box car is 10,000 kg

Let V is the speed of the cars just after the collision. It is based on the concept of inelastic collision. So, using the conservation of linear momentum we get :

So, the speed of the cars just after the collision is 0.875 m/s.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.