Question

A particle of mass m moves along line PC with velocity v as shown. What is the angular momentum of the particle about P?

• A. $mvL$
• B. $mvI$
• C. $mvr$
• D. $Zero$

Answer 1

The correct option is D

$Zero$

Step 1 Definition of angular momentum

Angular momentum is the property of a rotating body which is given by the product of the moment of inertia and the angular velocity of the rotating object.

$Angularmomentum\left(L\right)$ = $MomentofInertia\left(I\right)\times Angularvelocity\left(\omega \right)$

Step 2 Given data

Mass of the particle = m

The velocity of the particle = v

We know,

$Angularmomentum\left(L\right)=I\omega =m(\overrightarrow{r}\times \overrightarrow{v})$

Or, we can write it as

$L=vr\sin \theta$-----------(1)

Where $\theta$ is the angle between r and v

As angle between r and v is $0^0$

Now, In equation 1

$L=vr\sin 0^0=0$ ( As $\sin 0^0=0$)

Hence, angular momentum of the particle about P is zero.

The correct option is (D) Zero.