Un motociclista se acerca a una patrulla estacionaria con una rapidez de 13 m/s. La patrulla emite un sonido con una frecuencia de 500 Hz. ¿Qué frecuencia escucha el
motociclista? ¿Cuál es la longitud de onda del sonido emitida por la fuente y la
longitud de onda percibida por el motociclista?

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.

If a car is traveling on the highway at a constant velocity, the force that pushes the car forward must be a. equal to the weight of the car. b. less than the force of friction exerted upon the car. c. equal to the force of friction exerted upon the car. d. greater than the weight of the car.

What would be different if joe was moving a book instead of a file cabinet