Question

A 4kg and a 2kg block are moving along a horizontal frictionless surface. The 4 kg block is moving to the right with a speed of 6 m/s and the 2 kg block is moving to the left with a speed of 3 m/s. The two blocks collide inelastically and then continue to move together along the surface and then up a 30° frictionless ramp. How high up the ramp does the combined object move

Answer 1

Use conservation of momentum to get the final velocity of the stuck-together blocks. Then compute the new total kinetic energy using that velocity.

For the final step, use conservation of energy. Initial KE of the stuck blocks equals the potential energy gain at their highest point they get to on the ramp.