Una piedra de amolar al reducir su velocidad angular desde 1500 rpm hasta 800 rpm lograr 700 revoluciones. calcular: a) la desaceleración de la piedra b) el tiempo que requiere para esta disminución de velocidad c) si la velocidad continua reduciendo a la misma velocidad ¿cuánto tiempo más se requiere para quedar en reposo? resp. a) -2rad / s² b) 36,65s c) 41,9s

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.