**Goal:** Hone the concept of angular momentum

**Source:** UMPERG-ctqpe132

Which situation has the least (magnitude) angular momentum about the

origin?

- A 2 kg mass travels along the line y = 3m with speed

1.5 m/s. - A 1 kg mass travels in a circle of r = 4.5 m about the

origin with speed 2 m/s. - A disk with I = 3 kg-m
^{2}

rotates about its center (on origin) with ω = 3 rad/s.

- A
- B
- C
- Both A and B
- Both A and C
- Both B and C
- All have the same magnitude angular momentum

## Commentary:

## Answer

(7) Students frequently think that objects traveling in a straight line

have no angular momentum. An interesting follow up question is to ask

how students would answer if the disk in situation were rotating about

the point (1,0).