You have a ball in your hand above the ground at rest which you then drop. what energy is involved in each part of this situation and how do we know that total mechanical energy has been conserved? explain with and without air resistance present.

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

At very high pressures, gases become and will eventually a) more dense; become hotter b) more dense; change to a liquid or solid c) less dense; combust d) less dense; turn into a liquid

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.