An electric fan is turned off and its angular velocity decreases uniformly from 500rev/min to 200rev/min in 4.00s. a) Find the angular acceleration in rev/s2 and the number of revolutions made by the motor in 4.00s interval. b) How many more seconds are required for the fan to come to rest if the angular acceleration remain constant at the value calculated in part (a)

Why do different substances have diffrent properties

Aball is thrown from the top of a building with an initial velocity of 21.9 m/s straight upward, at an initial height of 51.6 m above the ground. the ball just misses the edge of the roof on its way down, as shown in the figure. (a) determine the time needed for the ball to reach its maximum height. (b) determine the maximum height. (c) determine the time needed for the ball to return to the height from which it was thrown, and the velocity of the ball at that instant. (d) determine the time needed for the ball to reach the ground. (e) determine the velocity and position of the ball at t = 5.35 s.

Four identical lab carts each have a mass of 200 kg. different masses are added to the carts and the velocities are measured. all carts move to the right.