question_answer

A particle of mass m is moving along the side of a square of side 'a', with a uniform speed u in the x-y plane as shown in the figure:                                                                [JEE MAIN - I 3-4-2016]

Which of the following statement is false for the angular momentum \[\vec{L}\] about the origin?

A)         \[\vec{L}=\frac{m\upsilon }{\sqrt{2}}R\hat{k}\] when the particle is moving from D to A

B)   \[\vec{L}=-\frac{m\upsilon }{\sqrt{2}}R\hat{k}\] when the particle is moving from A to B

C)        \[\vec{L}=m\upsilon \left[ \frac{R}{\sqrt{2}}-a \right]\hat{k}\] when the particle is moving from C to D

D)      None of these

Correct Answer: D

Solution :

[a, c]

or  or

For D to A

For A to B

For C to D

For B to C