# Worksheet: Angular Momentum in Terms of Moment of Inertia

In this worksheet, we will practice calculating the angular momentum of an object that is rotating from its moment of inertia.

**Q1: **

If the angular speed of a rotating object increases by a factor of 3, by what factor does the angular momentum of the object change?

**Q2: **

An object spinning with an angular speed of rad/s has an angular momentum of
kg⋅m^{2}/s.
What is the moment of inertia of the object about its axis of rotation?

**Q3: **

A hollow metal sphere has a moment of inertia about its axis of rotation of
0.45 kg⋅m^{2} and an angular momentum of
0.79 kg⋅m^{2}/s.
How long does it take for the sphere to make one full rotation?
Give your answer to 2 significant figures.

**Q4: **

The wheel of a car has a moment of inertia of
2.25 kg⋅m^{2}
about its axis of rotation. As the car is driven along a road,
the wheel has an angular momentum of
70.7 kg⋅m^{2}/s.
With what angular speed is the wheel rotating?

**Q5: **

An asteroid has a moment of inertia about its axis of rotation of
kg⋅m^{2}.
The asteroid makes one full rotation every
250 s.
What is the angular momentum of the asteroid? Give your answer to 2 significant figures.

- A kg⋅m
^{2}/s - B kg⋅m
^{2}/s - C kg⋅m
^{2}/s - D kg⋅m
^{2}/s - E kg⋅m
^{2}/s

**Q6: **

A solid metal sphere is rotating with an angular speed of
12.6 rad/s.
It has a moment of inertia of
0.0200 kg⋅m^{2}.
What is the angular momentum of the sphere?

**Q7: **

The wheel of a car has a moment of inertia of
2.25 kg⋅m^{2}
about its axis of rotation.
If the wheel makes 8 turns in 1 second,
what is the angular momentum of the wheel? Give your answer to 3 significant figures.

**Q8: **

A solid metal disk has a moment of inertia of 0.025 kg⋅m^{2}
about its axis of rotation and has an angular momentum of 14 kg⋅m^{2}/s.
With what angular speed is the disk rotating?

**Q9: **

An object has a moment of inertia of
0.50 kg⋅m^{2}
about its axis of rotation and an angular momentum of
130 kg⋅m^{2}/s.
How many times does the object rotate in 1 second? Give your answer to 2
significant figures.

**Q10: **

A stick being spun about its center has an angular momentum of 0.320 kg⋅m^{2}/s.
The stick is being spun at an angular speed of 25.1 rad/s.
What is the moment of inertia of the stick about its axis of rotation?

**Q11: **

Earth has a moment of inertia about its axis of rotation of
kg⋅m^{2}
and an angular speed of
rad/s.
What is the angular momentum of Earth due to its rotation?

- A kg⋅m
^{2}/s - B kg⋅m
^{2}/s - C kg⋅m
^{2}/s - D kg⋅m
^{2}/s - E kg⋅m
^{2}/s

**Q12: **

The magnetic disk in a hard disk drive is spinning with an angular speed of
rad/s.
The magnetic disk has a moment of inertia of
0.00049 kg⋅m^{2}/s.
What is the angular momentum of the disk?

**Q13: **

The SI unit of angular momentum is
kilogram - square meters per second (kg⋅m^{2}/s). The SI
unit of moment of inertia is
kilogram - square meters (kg⋅m^{2}). If angular momentum is divided
by moment of inertia, what is the SI unit of the resultant quantity?

- As
^{−1} - Bs
^{−2} - Cs
- Dkg/s
- Em/s

**Q14: **

The SI unit of angular momentum is kilogram - square meters per second (kg⋅m^{2}/s). If
angular momentum is divided by frequency, what is the SI unit of the resultant quantity?

- Akg⋅m⋅s
- Bkg⋅m/s
- Ckg⋅m
^{2} - Dkg⋅m
^{2}⋅s - Ekg⋅m
^{2}/s