Waves move fastest in
low-temperature gases.
low-temperature solids.
high-temperature gases
high-temperature solids.

The earth remains in orbit around the sun due to the force of gravity. how does the force of gravity exerted by the sun on the earth compare to the force of gravity exerted by the earth on the sun?

What are similarities and differences of reflection, refraction, diffraction and absorption?

Apulley system is used to lift a 2,000 newton engine up a distance of 3 meters. the operator must apply a force of 250 newtons to the chain of the pulley system to lift the motor. to lift the engine 3 meters, the operator must pull a total of 30 meters of chain through the pulley system. what is the value of di?