University of Texas - PHY 303

1)If the mass of the bar is mass m = 1.53 kg, find the magnitude of the horizontal compo- nent of the force of the wall acting on the bar

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A figure skater on ice spins on one foot. She pulls in her arms and her rotational speed increases.

Choose the best statement below:

1. Her angular speed increases because her potential energy increases as her arms come in.

if the string makes an angle of 32.7

horizontal.

with the

2

Her angular speed increases because by

The acceleration of gravity is 9.8 m/s  .

Take torques about the pin:

pulling in her arms she creates a net torque in the direction of rotation.

1. Her angular speed increases because her angular momentum increases.

2. Her angular speed increases due to a net torque exerted by her surroundings.

3. Her angular speed increases because her angular momentum is the same but her mo- ment of inertia decreases. correct

4. Her angular speed increases because air friction is reduced as her arms come in.