activity #3 (GenP601)

A wheel spinning at 3 m/s uniformly accelerates to 6 m/s in 4 s. Its radius is 20 cm. How far around the wheel will a speck of dust travel during that interval?

• 6 m

• 9 m

• 12 m

• 18 m

• 30 m

If an object of radius 3 m that experiences a constant angular acceleration starting from rest, rotates 10 rads in 2 s, what is its angular acceleration?

• 2.5 rad/s2

• 5 rad/s2

• 7.5 rad/s2

• 10 rad/s2

• 15 rad/s2

A bicycle moves at constant speed over a hill along a smoothly curved surface as shown above. Which of the following best describes the directions of the velocity and the acceleration at the instant it is at the highest position?

• The velocity is towards the right of the page and the acceleration is towards the top of the page.

• The velocity is towards the right of the page and the acceleration is towards the bottom of the page.

• The velocity is towards the right of the page and the acceleration is towards the bottom right of the page

• The velocity is towards the right of the page and the acceleration is towards the top right of the page

• The velocity is towards the top right of the page and the acceleration is towards the bottom right of the page.

An object weighing 10 N swings at the end of a rope that is 0.72 m long as a simple pendulum. At the bottom of the swing, the tension in the string is 12 N.

What is the magnitude of the centripetal acceleration at the bottom of the swing)?

• 2 m/s2

• 4 m/s2

• 10 m/s2

• 12 m/s2

• 22 m/s2

What is the speed of the object at the bottom of the swing?

• 0.6 m/s

• 1.2 m/s

• 2.0 m/s

• 2.4 m/s

• 7.2 m/s

Base your answers to questions 6 and 7 on the picture below, which represents a rigid uniform rod with a mass of 6 kg and a length of 1.0 m is pivoted on the right end. It is held in equilibrium by an upward force of 40 N.

How far from the left end of the rod should the force be placed to maintain equilibrium?

• 10 cm

• 20 cm

• 25 cm

• 40 cm

• 50 cm

Base your answers to questions 6 and 7 on the picture below, which represents a rigid uniform rod with a mass of 6 kg and a length of 1.0 m is pivoted on the right end. It is held in equilibrium by an upward force of 40 N.

What force is applied to the rod by the pivot?

• 10 N

• 20 N

• 40 N

• 60 N

• 100 N

The angular velocity of a rotating disk with a radius of 2 m decreases from 6 rads per second to 3 rads per second in 2 seconds. What is the linear acceleration of a point on the edge of the disk during this time interval?

• Zero

• –3 m/s²

• –3/2 m/s²

• 3/2 m/s²

• 3 m/s²

A solid sphere of radius 0.2 m and mass 2 kg is at rest at a height 7 m at the top of an inclined plane making an angle 60° with the horizontal. Assuming no slipping, what is the speed of the cylinder at the bottom of the incline?

• Zero

• 2 m/s

• 4 m/s

• 6 m/s

• 10 m/s

What is the moment of inertia of a spinning object of radius 0.5 m and mass 6 kg moving at 5 m/s, if it has a kinetic energy of 100 J?

• 1 kg/m²

• 2 kg/m²

• 4 kg/m²

• 8 kg/m²

• 20 kg/m²