Electromagnetic waves emitted by an omnidirectional broadcast antenna on earth strike a 4.23-m^2 flat surface that forms part of an artificial satellite that is located 251 km from the antenna. the surface is oriented perpendicular to the propagation direction of the waves and acts as a perfect reflector. what power output in gigawatts would be required from the antenna in order to acheive a radiation force of 1.87n on the surface?

The speed of sound in ice, water, and steam is shown. what best explains the speed of sound in different states of matter? sound travels fastest in ice because energy is easier to transfer when the molecules are close together. sound travels slowest in steam because the sound has to move around the gas molecules that are far apart. sound travels fastest in ice because the temperature of solids is always greater, so the heat transfers the sound energy. sound travels slowest in steam because the pressure is so great the sound cannot travel though the steam particles.

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

What is the orbital period of a spacecraft in a low orbit near the surface of mars? the radius of mars is 3.4×106m.