In order to generate electricity, nuclear power plants take advantage of this part of the electromagnetic spectrum. gamma rays radio waves ultraviolet rays visible light

Currently, commercial nuclear reactors  in use work with nucler fission, which consists in the separation of the components of the atom nucleous. Normally, a large nucleus such as uranium is divided into two smaller nuclei by fission, along with a few neutrons and a release of energy in the form of heat (kinetic energy) and gamma rays.

In this sense, gamma rays are a type of electromagnetic radiation, and therefore constituted by photons, usually produced by radioactive elements. This type of radiation can travel long distances through the air and pass through various materials including the tissues of the human body, so that only large protections of lead or concrete can stop these rays.

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s