A bicyclist starts from rest and begins riding down the street. After her wheels have rotated through ten revolutions, they have acquired an angular velocity of 21 rad/s. Determine the angular acceleration of her wheels. Express your answer in radians per second squared. a = 195) ΑΣΦ ? rad/s²

A 200-gram car is at rest at the top of a 0.8-meter high ramp (point A). When the car is released, it rolls to the bottom of the ramp at a speed of 3.50 m/s. At the bottom of the ramp (point B), the car hits a box and skids to a stop at 10 meters (point C). Calculate the energy at the top and bottom of the ramp. (bottom of the ramp is 3.50 m/s). Calculate the energy loss using the formula (|Einitial-Efinal| / Einitial) x 100. Assume there is friction that brings the car to a stop from point B to point C and that it is related to the normal force as f=μFN. Use Work and the provided measurements to determine the coefficient of friction between the box and the surface.

(a) How much work is done when you push a crate horizontally with 100 N across a 10-m factory floor? (b) If the force of friction on the crate is a steady 70 N, show that the KE gained by the crate is 300 J. (c) Show that 700 J is turned into heat.

A 20-foot chain weighing 5 pounds per foot is lying coiled on the ground. How much work is required to raise one end of the chain to a height of 20 feet so that it is fully extended, as shown