1. Starting from rest, a 20 kg wheel rolls down a hill of height 6 m....

1. Starting from rest, a 20 kg wheel rolls down a hill of height 6 m. At the bottom of the hill 360 J of of energy is in its rotation. What is the speed of the wheel's center of mass?

6 m/s

8 m/s

10 m/s

9 m/s

4 m/s

2. If each of the following objects are rotating with the same angular velocity, ?, which would be the hardest to stop? (i.e., require the largest amount of work).

A hoop with mass (1/2)M and radius 2R rotating about its cylinder axis.

A solid cylinder with mass 4M and radius (3/4)R rotating about its cylinder axis.

A solid sphere with mass 8M and radius (2/3)R rotating about any diameter.

A hoop with mass 4M and radius (1/2)R rotating about its cylinder axis.

A thin spherical shell with mass 8M and radius (1/2)R rotating about any diameter.

3. If an object is in equilibrium, which of the following are true? There may be more than one correct answer.

There can only be one torque on the object.

The net torque on the object is zero.

The object may be at rest.

The object may have a constant velocity.

The net force on the object is zero.

Solutions

Expert Solution

genius_generous answered 1 year ago

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