An object is falling from a terrace (height 20 m). At what point does it have maximum kinetic energy?
Just before touching the ground floor
From the law of conservation of energy, we know that at the height of 20 m, the object will have maximum potential energy and when it reaches the ground floor, it has maximum kinetic energy.
Since the velocity of the object increases when it comes down, its kinetic energy will be maximum just before touching the ground. When the object touches the ground, part of its kinetic energy is transformed into sound energy and part of the energy is lost to the surroundings.