The electric motor has an input energy of 50,000 joules each second. The motor transfers 35,000 joules of useful energy each second. Calculate the efficiency of the electric motor (show workig out too)

What causes a neap tide?

Calculate the speed of a proton having a kinetic energy of 0.995 * 10-19 J and a mass of 1.673 * 10-27 kg. Answer in units of m/s.

A water skier has a mass of 79 kg and accelerates at 1.4 m/s^2. The net force acting on her is

Infrared observations of the orbits of stars close to the galactic center indicate a small object at the center with a mass of about how many solar masses?

The U. S. Navy has long proposed the construction of extremely low frequency (ELF waves) communications systems; such waves could penetrate the oceans to reach distant submarines.

For each of the following, describe the relationship as directly or inversely proportional: a) wavelength vs. frequency b) wavelength vs. energy c) frequency vs. energy ... ?

Can hand sanitizer be used as rubbing alcohol

Two objects experience a 12 N electrical force between them. What force will the objects experience if the distance between them is doubled?

a submarine moving directly upward in the water at constant speed. The weight of the summer and it is 500,000 N. The submarines motors are off. The magnitude of the buoyant force acting on the submarine is

If the car went 30 km west in 25 min. and then 40 km east in 35 min., what would be its total displacement?