MCQ
A body is projected with velocity $u$ making an angle $\alpha$ with the horizontal. Its velocity when it is perpendicular to the initial velocity vector $u$ is
- A$u \,tan\alpha$
- ✓$u\, cot\alpha$
- C$u\, cosec\alpha$
- D$u \,sec\alpha$
✓
Answer
Correct option: B.
$u\, cot\alpha$
b
$'O' = u\cos \alpha $
$'O' = u\cos \alpha $
$'P' = v\sin \alpha $
$v\sin \alpha = u\cos \alpha $
$\Rightarrow \,v = u\cot \alpha $
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