Rotational Motion

A 0.12-m-radius grinding wheel takes 5.5 s to speed up from 2.0 rad/s to 11.0 rad/s. What is the wheel's average angular acceleration?

• 9.6 rad/s/s
• 4.8 rad/s/s
• 3.1 rad/s/s
• 1.6 rad/s/s

A fan blade, initially at rest, rotates with a constant acceleration of 0.025 rad/s². What is the time interval required for it to reach a 4.2 rad displacement after starting from rest   

• 1.8 s
• 2.0 s
• 16 s
• 18 s

A flywheel starts from rest, and has an angular acceleration of 4 rad/s². What will be its angular speed when it has made one revolution? 

• 5.01 rad/s
• 50.27 rad/s
• 2.83 rad/s
• 7.09 rad/s

What is 2 radians in degrees?

• 57.3

• 114.6

• 26.65

What is the average angular velocity in radians if a paint spot on a tire turns from 57.3 degrees to 282 degrees in .5 sec

• 339.3

• 7.8

• 1.95

• 4.9

A toy train moves in a circular track with a velocity of 2.2 m/s, the axis of rotation is 1.8 m. What is its centripetal acceleration?

• 1.22 m/s²

• 0.81 m/s²

• 2.69 m/s²

• 1.47 m/s²

Calculate the centripetal force required to make a 5 kg ball move 4 m/s in a circle with a radius of 2 m.

• 10 N
• 20 N
• 30 N
• 40  N

A Ferris wheel has a radius of 50 meters and takes approximately 800 seconds to make a full circle. Determine the tangential speed of riders (in m/s)

• .39 m/s

• 314 m/s

• 40,000 m/s

a car going around a curve - identify the centripetal force:

• friction

• tension

• force normal

• force weight

The velocity is always _____ to the circle.

• outwards

• towards the center

• tangent

• faster