Question:

A small object of uniform density rolls up a curved surface with an initial velocity v'. It reaches up to a maximum height of 3v²/4g with respect to the initial position. The object is

Solid sphere

Disc

Ring

Hollow sphere

v² = 2gh/(1 + k²/r²)
v² = 2g(3v²/4g)(1 + k²/r²)
=> 1 + k²/r² = 3/2
k²/r² = 1/2
=> disc