Question

A torque of $1N-m$ is applied to a wheel which is at rest. After $2$ seconds the angular momentum in $kg-m^2/s$ is

• A. 0.5
• B. 1
• C. 2
• D. 4
• E. 3

Answer 1

Answer: (C)

As; $\tau =I\alpha$
So, $\alpha =\frac{\tau }{I}$
Now $W=\alpha \Delta t$
And $L=IW$
$=I\alpha \Delta t$
$=I\frac{\tau }{I}\Delta t=\tau \Delta t$
$=1(N.m)\times 2(s)$
$=2kg{m}^2{s}^{-1}$