A substance made up of 2 or more elements is called

Asteroids orbit the sun like planets do. why are aseroids not consideed to be planets?

Why is it very difficult for astronomers to find objects like planets and asteroids?

Which has more kinetic energy, a feather floating through the air or a rock on the ground? Explain.

What is the period of a satellite in a circular orbit just above the surface of the Moon? The Moon's mass is 7.36 * 1022 kilograms and its radius is 1.738 * 106 meters.

If two waves with identical crests and troughs meet what is happening?

Two copper wires with different diameters are joined end to end. If a current flows in the wire combination, what happens to electrons when they move from the larger-diameter wire into the smaller-diameter wire?

A baseball player is warming up and tosses a ball straight up into the air. The ball travels up until it reaches some maximum height, and then falls back down to the player/'s hand.

Volume can be measured in liters or cubic meters. a. T b. F

A spring with a spring constant of 1200 N/m has a 55-g ball at its end. The energy of the system is 5.5J. What is the amplitude of vibration?

Force F1 acts on a particle and does work W1. Force F2 acts simultaneously on the particle and does work W2. The speed of the particle does not change. Which one of the following must be true? a. W1 is zero, and W2 is positiveb. W1 = - W2c.