A fan rotating with an initial angular velocity of 1500 rev/min is switched off. In 2.5 seconds, the angular velocity decreases to 400 rev/min. Assuming the angular acceleration is constant, answer the following questions. How many revolutions does the blade undergo during this time?
A) 10
B) 20
C) 100
D) 125
E) 1200

The blade undergoes 40 revolutions, so neither of the given options is correct!

Explanation:

The revolutions can be found using the following equation:

Where:

α is the angular acceleration

t is the time = 2.5 s

is the initial angular velocity = 1500 rev/min                

First, we need to find the angular acceleration:

Now, the revolutions that the blade undergo are:

Therefore, the blade undergoes 40 revolutions, so neither of the given options is correct!

I hope it helps you!                              

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.

cant without the picture! ?