Physics Rotation

What is the unit of moment f force?

• N

• m

• Nm

• N/m

A grindstone spinning at the rate of 8.3 rev/s has what approximate angular speed?

• 3.2 rad/s

• 26 rad/s

• 52.12 rad/s

• 81 rad/s

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

• 1.63 rad/s/s

Which would have a greater tangential velocity?

• Kid near the center of the merry go round

• Kid near the outside of the merry go round

• neither

• Both kids have same tangential velocity

An object completes 1.5 circular orbits in half a minute. What is its approximate angular velocity?

• 0.05 rad/s

• 0.31 rad/s

• 0.5 rad/s

• 3 rad/s

Tags

NGSS.HS-ESS1-4

Tangential velocity (v_t) is the product of

• r and ω

• r and ϴ

• s and r

• θ and t

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.

• 18.33 s

• 18.0 s

• 18.90 s

• 16.33 s

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?

• 6.13 rad/s/s

• 1.63 rad/s/s

• 3.16 rad/s/s

• 6.31 rad/s/s

An ice skater is spinning in a circle with his arms extended out. He then brings his arms in, what happens to his rotational velocity?

• It increases

• It decreases

• It stays the same

• He stops spinning immediately

A Ferris wheel, rotating initially at an angular speed of 0.50 rad/s, accelerates over a 7.0 sec interval at a rate of 0.040 rad/s². What is its angular speed after this 7 sec interval?

• 0.2 rad/s

• 0.3 rad/s

• 0.46 rad/s

• 0.78 rad/s