A particle of mass m is travelling with a constant velocity $\overrightarrow {V} =V_0 \hat i$ along the line $y=b,z=0$. Let $dA$ be the area swept out by the position vector from the origin to the particle in time at end L be the magnitude of angular momentum of particle about orgin at any time t. Then 1) L= constant 2) $\large\frac{dA}{dt}=\frac{L}{m}$ 3) $\large\frac{dA}{dt}= \frac{2L}{m}$ 4) $\large\frac{dA}{dt}=\frac{L}{2m}$ Which of the following is correct?