What is the central equation of mass-energy equivalence?

Two new planets are discovered, planet X and planet Y. The planets have identical volumes, but the mass of planet X is two times greater than the mass of planet Y.

How does Earth's atmosphere make conditions on Earth suitable for living things?

A young girl gives her toboggan a push of 4.0m/s uphill. It slides up the hill slowing down at an acceleration of 8.0m/s down. It comes to a stop and then slides back towards her speeding up at the same rate as it slowed down on the way up.

What happens after the Gulf Stream travels north? It cools and flows away from the pole, causing cooler climates farther south. It circles the poles, becoming ice. It crashes with incoming warm water.

If the station is 40 km away, how long does it take for the radio waves to reach you from the station? Answer in units of seconds.

Which phases of matter do molecules have the lowest amount of energy?

How many Oxygen (O) atoms are in the following? H2O + CO2 4 3 2

How does surface roughness affect friction

Why does it hurt your hands when you carry heavy shopping in carrier bags?

Why did scientists choose carbon as a base for the atomic mass unit? Which isotope of carbon did they use?