Which of these are not mechanical waves and can be used to send a signals to satellites orbiting the earth?

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.

The answer is orbit around nucleus

The independent variable would be the fertilizer as it is what the dependent variable (the growth of grass) depends on.

Answerhave high resistance to flow