A4.00 m length of light nylon cord is wound around a uniform cylindrical spool of radius 0.500 m and mass 1.00 kg. the spool is mounted on a frictionless axle and is initially at rest. the cord is pulled from the spool with a constant acceleration of magnitude 2.95 m/s2.

(a) how much work has been done on the spool when it reaches an angular speed of 6.70 rad/s?
(b) assuming that there is enough cord on the spool, how long does it take the spool to reach this angular speed?
(c) what length of cord is pulled from the spool when the angular speed is reached?

Atennis player used a tennis racket to hit a tennis ball with a mass of 0.25 kg with a force of 5.25 newtons. how does the force the tennis racket exerted on the tennis ball compare with the force the tennis ball exerted on the tennis racket? a. the force of the tennis racket on the tennis ball is equal in magnitude and opposite in direction to the force the tennis ball exerted on the tennis racket. b. the force of the tennis racket on the tennis ball is equal in magnitude and in the same direction as the force the tennis ball exerted on the tennis racket. c. the force of the tennis racket on the tennis ball is less in magnitude and in the same direction as the force the tennis ball exerted on the tennis racket. d. the force of the tennis racket on the tennis ball is greater in magnitude and opposite in direction as the force the tennis ball exerted on the tennis racket.

What is an electric motor? explain its operation. 2-3 sentence

Is the number of complete movements of a wave per second.