Question

How does increasing the height of an object affect its mechanical energy

Answer 1

mechanical energy has two parts kinetic energy and potential energy. and potential energy is mostly depended on the weight of an object. Where as kinetic is depended on height. height h becomes kinetic energy once that object falls back to its original height... This conservation of mechanical energy actually applies only in the ideal case where friction (in all its forms) is neglected.
So it adds more kinetic energy when height is added.

Answer 2

The amount of work required to raise the TV from point A to point B is equal to the amount of gravitational potential energy the TV gains from its height above the ground. This is generally true for any object ...