Question

Problem 1:

A wheel starts from rest and rotates with constant angular acceleration and reaches an angular velocity of 32.0 rad/s in 4.00 s.

(a) What is the magnitude of the angular acceleration of the wheel?

(b) Through what angle does the wheel rotate in these 4.00 s?

Problem 2:

An automobile traveling at 90.0 km/hour, has tires of 75.0 cm diameter.

(a) What is the angular velocity of the tires about the axis of rotation?

(b) If the car is brought to a stop uniformly in 60.0 turns of the tires (without slipping), what is the angular acceleration of the wheels?

(c) How far does the car move during the braking?

Problem 3:

A fan is started from rest and after 8.0s has reached its maximum rotational velocity of 60 radians per second.

1. Find the average angular acceleration

2. How many revolutions the fan makes while accelerating assuming constant acceleration?

3. What was the angular displacement between 5.0 s and 8.0 s after the fan started rotating?

Answer 1

Solution) (1) wo = 0 ( rest )

w = 32 rad/s

t = 4 s

(a) Angular acceleration of the wheel = ?

Angular acceleration = ( w - wo )/(t)

Angular acceleration = ( 32 - 0 )/(4) = 8 rad/s^2

Angular acceleration = 8 rad/s^2

(b) Angle , theeta = ?

w^2 = wo^2 + 2(angular acceleration)(theeta)

(32^2) = 0 + 2(8)(theeta)

Theeta = (32^2)/(16)

Theeta = 64 rad

* kindly post next questions in next post