A 3 kg moves with constant speed of `2ms^(-1)` in the xy-plane in the y-direction along the line x = 4 m. the angular momentum ( in `kg-m^(2)s^(-1)`) relative to the original and the torque about the original needed to maintain this motion are respectively

Options

A. 12, 0
B. 24, 0
C. 0, 24
D. 0, 12

Answer

B

Explanation

Here, `m=3kg, v=2ms^(-1) r= 4m, L=? And T = ?`

`L=mvr sin 90^(@)=3xx2xx4xx1="24 kg-m"^(2)s^(-1)`
`because` Particle moves with constant speed
`therefore` L = Constant
`"and "tau=(dL)/(dt)=0`