When the angular momentum changes, the 'change' in the angular momentum vector (ie. dL) is ____.

Question

When the angular momentum changes, the 'change' in the angular momentum vector (ie. dL) is ____.

[a.] perpendicular to the torque vector.
[b.] parallel to the angular momentum vector.
[c.] parallel to the torque vector.

.. im confused on this one.. i think it's [A]. am i right? :\

No, (a) is incorrect. Just as acceleration or momentum change is parallel to the force causing it, the change in angular momentum is parallel to the torque causing it.

The correct answer is (c)

thanks. i had a feeling it was (C)..

Answer 1

You're welcome! I'm glad I could help. If you're ever unsure about a concept like this in the future, it can be helpful to think about the cause and effect relationship between torque and angular momentum. The torque is what causes a change in angular momentum, so the change in angular momentum will be parallel to the torque vector.