Mechanical (sound) waves are unable to travel through a vacuum such as through space but radio waves are transmitted to earth from satellites. how is this possible

What are similarities and differences between refraction, reflection, diffraction and absorption?

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

An electric clothes dryer has a resistance of 8 ohms. it draws 30 a of current. what is the voltage, in volts, of the wall outlet that it is plugged into?