Physics

Let's use the principle of conservation of momentum to solve this problem.

 

Given:

Mass of the first object:

Velocity of the first object before the collision:

Mass of the second object: (unknown)

Velocity of the second object before the collision: (stationary)

Final velocity of the combined objects after the collision:

 

Apply Conservation of Momentum

Since no external horizontal forces are acting on the system, the total momentum before and after the collision must be equal.

 

Substitute the known values: