A ball took 0.45s to hit the ground 0.72m from the table. What was the horizontal velocity of the ball as it rolled off the table?

How does n relate to the number of electrons allowed per main energy level

Is a spring that is stretched a kinetic, potential or both?

You do work on something when you lift it against gravity. If the lifted object is released, what becomes of this energy? Be sure to define all terms that you use.

True or false? Atoms that have the same number of neutrons but different numbers of protons are called isotopes. WHY?

reddit One company sells a defibrillator for home use that uses a 9-volt DC battery. The battery is rated at 4.2 A•hr (amp•hour). Roughly how much charge can the battery deliver?

If element X has 17 protons, how many electrons does it have?

A 2.0-kilogram laboratory cart is sliding across a horizontal frictionless surface at a constant velocity of 4.0 meters per second east. What will be the cart's velocity after a 6.0-newton westward force acts on it for 2.

A boat floats with 25% of its volume under water. a. What is the boatâs density? b. If the boat was made from 500 kg of metal, what is the volume of the boat? (Assume the air in the boat has negligible mass and density) c.

Why does each mineral have their own property, different from every other mineral?

Earth's tallest mountain ranges are found at plate boundaries