A lightweight object and a very heavy object are sliding with equal speeds along a level frictionless surface. They both slide up the same frictionless hill with no air resistance. Which object rises to a greater height?

No object rises a greater height. They both rise the same height.

Explanation:

Since the kinetic energy = work done by gravity

1/2mv² = mgh

h = v²/2g where h is the height and v the speed.

Since the speed is the same for both objects, the height moved is the same since the expression for the height moved is independent of their masses but dependent on their speeds.

So, no object rises a greater height. They both rise the same height.

they should be similar or the same