A small cube, with a mass of 3 kg, slides along a frictionless horizontal surface at a constant speed of 15 m/s until it collides with, and sticks to, a large wooden 4.5 kg
block. The large block is attached to the left end of a spring with a spring constant of
80 N/m as shown in the diagram.

Learned about life itself

Iam looking for this answer too!

Aform of energy that is reflected or emitted from objects in the form of electrical and magnetic waves that can travel through space. there are many forms of  electromagnetic  energy including gamma rays, x rays, ultraviolet radiation, visible light, infrared radiation, microwaves and radio waves.

Dshould be the right answer i think