🎴 Flashcard Mode
Angular momentum in case of rotation about a fixed axis - class-XI
Card1 / 84
Mastered0
Review0
QuestionClick to flip
A particle of mass m travels with a speed v along positive direction of x-axis parallel to the line y=4. At t=0, the particle is at (0,4),. The angular momentum of the particle about the origin is
AnswerClick to flip back
A
4 mv directed along the negative z- axis
💡 Explanation:
The correct option is C
We have,
$Mass=m,Speed=v$
A particle is moving along a straight line parallel to the y-axis.
So, position vector $(\hat r ) = 4 \hat j$
velocity of body $\hat V = v \hat i$
Since we know,
Angular momentum = $m(\hat r \times\hat V)$
$=m ( 4 \hat j \times v \hat i)$
$=-4mv\hat k$
Since,
$I \times j = k$
And, $j \times i = - k$