Wavelength of e.m.radiation is tripled. What will happen to its energy?

Wavelength of electromagnetic radiation is doubled, what will happen to energy of photon?

When the height of an object is increased, what happens to its potential energy?

A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy?

A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy.

Show that the wavelength of electromagnetic radiation is equal to the de-Broglie wavelength of its quantum (Photon).