Solution :
Given :
M = 0.35 kg

Total mechanical energy = constant
or 
But
and 
Therefore, potential energy at the top = kinetic energy at the bottom


(h = 35 cm = 0.35 m)
= 2.62 m/s
It is the velocity of M just before collision of 'm' at the bottom.
We know that in elastic collision velocity after collision is given by :

here, 
∴ 

= 0.33 m/s
Therefore, velocity after the collision of mass M = 0.33 m/s
Momentum is a product mass and velocity. If a certain object posses a kinetic energy, then it should have a momentum since it is moving which has a velocity. However, if the object is at rest and only has potential energy, then it would not have momentum. So, for the first question the answer would be yes, an object can have energy without having any momentum. For the second question, every object whether it is moving or at rest, possess some energy, potential for an object at rest and kinetic for an object that is moving. Thus, the answer would be no, an object having momentum would always have energy.
When object travels with uniform velocity, no force acts on it. hence , yes.
I think its a tbh bc it seems to be the best answer out of a b c and d