A 500-kg elevator is raised to a height of 20 m in 10 seconds. Calculate the power of the motor.

Where is the potential energy throughout the loading, cocking, and releasing of the trebuchet?

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?