A rock is dropped from the top of a cliff. It strikes the ground with a speed of 24 m/s. (a) How high is the cliff? (b) How long did it take the rock to fall to the ground?

Ababy stroller is a rest on top of a hill which is 10 m high. the stroller and baby have a mass of 20 kg. what is the potential energy of the baby and stroller?

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?

The force needed to overcome static friction is usually less than that needed to overcome kinetic friction.true or false?