A2L Item 173

Goal: Hone the concept of angular momentum

Source: UMPERG-ctqpe132

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

  1. A 2 kg mass travels along the line y = 3m with speed
    1.5 m/s.
  2. A 1 kg mass travels in a circle of r = 4.5 m about the
    origin with speed 2 m/s.
  3. A disk with I = 3 kg-m2
    rotates about its center (on origin) with ω = 3 rad/s.
  1. A
  2. B
  3. C
  4. Both A and B
  5. Both A and C
  6. Both B and C
  7. All have the same magnitude angular momentum



(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).