angular acceleration

A 0.12-m-radius grinding wheel takes 3 s to speed up from 2.0 rad/s to 11.0 rad/s. What is the wheel's average angular acceleration?

A fan blade, initially at rest, rotates with a constant acceleration of 0.25 rad/s². How many radians does it rotate after 4s?

• 18 rad

• 8rad

• 4rad

• 2rad

Which has more rotational inertia? (consider all objects have equal radius)

• Hollow sphere
• solid sphere
• disk
• cylinder

Which has greater linear speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail?

• the inside horse
• the outside horse
• Neither

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

The relation between linear velocity and angular velocity

• ⍵ = vr

• v = r⍵

• a = v⍵

The unit of angular velocity is

• m/s

• m/s²

• rad/s

• rad/s²

Centripetal acceleration is directed

• directed away from the center of the circle

• directed towards the center of the circle

• it is perpendicular to the radius at that point

• It has no direction

The expression for centripetal acceleration is

• a = v⍵

• a = r⍵²

• a = v²/r

• All of the above

An automobile tire rotates at an angular acceleration of 2.0 rad/s² starting from rest. How many radians does it rotate after 5s?

• 25 rad

• 12.5 rad

• 2 rad

• 0.5 rad