MCQ
At what angle of elevation, should a projectile be projected with velocity $20 \,ms ^{-1}$, so as to reach a maximum height of $10 \,m$ ?
- A$0$
- B$90$
- ✓$45$
- D$60$
✓
Answer
Correct option: C.
$45$
c
(c)
(c)
$H =\frac{ u ^2 \sin ^2 \theta}{2 g }$
$10=\frac{20 \times 20 \sin ^2 \theta}{20}$
$\sin ^2 \theta=\frac{1}{2}$
$\sin \theta=\sqrt{\frac{1}{2}}$
$\theta=45^{\circ}$
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