Verified answer

You haven't said what the related question is, other than mentioning a trolley and ramp.

The formula you give is for velocity if you know kinetic energy, KE

KE = (1/2)mv^2

2KE/m = v^2

v = √(2KE/m)

Here's an example. If a trolley rolls downhill from rest (no friction) and the height change is h, what is the speed at the bottom?

Loss of gravitational potential energy = Gain in kinetic energy (because of conservation of energy)

mgh = KE

v = √(2KE/m)

= √(2mgh/m)

=√(2gh)

Height affects gravitational PE. The gravitational PE is equal to the KE it gets at the bottom of the ramp.