When can we be certain that the average velocity of an object is always equal to its instantaneous velocity?

What is most likely true of an atom with a mass of 15 amu? A) There are 15 protons. B) There are 15 electrons. C) The total number of protons and electrons is 15. D) The total number of protons and neutrons is 15.

If an object is at rest, can we conclude that no external forces are acting on it?

List four ways of separate a mixture

What organisms disappeared duing Precambrian

3. Why can't most therapists and counsellors prescribe drugs? Wouldn't that be a good thing?

1. A 0.828-nm photon collides with a stationary electron. After the collision, the electron moves forward and the photon recoils backwards. a) Find the momentum of the electron. b) Find the kinetic energy of the electron.

When are you most aware of your motion in a moving vehicle: when it is moving steadily in a straight line or when it is accelerating?

The force of gravity on a person or object on the surface of a planet is called?

What happens to the particles of the liquid inside a thermometer when the thermometer is heated? They slow down and spread apart. They speed up and spread apart. They slow down and move closer together. They speed up and move closer together.

You did 150 joules of work lifting a 120 - N backpack. how high did you lift the backpack? how much did the backpack weigh in pounds