JEE Main · 2025 · 04 Apr 2025 · Shift 1 · Kinematics

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L

and

P

represent the angular momentum and linear momentum respectively of a particle of mass ' m ' having position vector

r = a (\hat{i} cos ω t + \hat{j} sin ω t)

. The direction of force is

(A)Opposite to the direction of $r$ ✓ Correct
(B)Opposite to the direction of $L$
(C)Opposite to the direction of $P$
(D)Opposite to the direction of $L \times P$

Answer: (A)

Solution

The position vector

r = a (\hat{i} cos ω t + \hat{j} sin ω t)

describes uniform circular motion of radius

a

. Differentiating twice in time, the acceleration is

a = - ω^{2} r

, pointing toward the centre. The force

F = m a = - m ω^{2} r

is therefore directed opposite to the position vector

r

JEE Main · 2025 · 04 Apr 2025 · Shift 1 · Single correct option

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