Question

The torque acting on a body about a given point is given by $ \tau = \overrightarrow{A} \times\overrightarrow{L} $ where $ \overrightarrow {A} $ is a constant vector and $ \overrightarrow {L} $ is the angular momentum of the body about this point. It follows that

• A. the magnitude of $ \overrightarrow {L} $ does not change with time
• B. the component of $ \overrightarrow {L} $ in the direction of $ \overrightarrow {A} $ does not change with time
• C. $ \frac {d\overrightarrow L} {dt} $ is perpendicular to $ \overrightarrow {L} $ at all instants of time
• D. All of the above choices are correct

Answer 1

The Correct Option is D

$ \tau = A \times L$ $A = $ constant vector $L =$ angular momentum In $A$ and $L$ there will be no change. So. all the above choices are correct.