Physics Two Dimensional Motion Question 60

Question: A particle is projected from point $ O $ with velocity $ u $ in a direction making an angle $ \alpha $ with the horizontal. At any instant its position is at point $ p $ at right angles to the initial direction of projection, Its velocity at point $ p $ is

Options:

A) $ u\tan \alpha $ B) $ u\cot \alpha $ C) $ ucosec\alpha $ D) $ u\sec \alpha $

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Answer:

Correct Answer: B

Solution:

[b] Horizontal velocity at point ‘[O’=u cos$ \alpha $ Horizontal velocity at point ‘P’=v sin $ \alpha $ In projectile motion horizontal component of velocity remains constant throughout the motion $ \

Therefore v\sin \alpha =u\cos \alpha $

$ \Rightarrow v=u\cot \alpha $