Question
The initial speed of a projectile fired from ground is $u$. At the highest point during its motion, the speed of projectile is $\frac{\sqrt{3}}{2} u$. The time of flight of the projectile is:
✓
Answer
$u \cos \theta=\frac{\sqrt{3} u }{2} \Rightarrow \cos \theta=\frac{\sqrt{3}}{2}$
$\Rightarrow \theta=30^{\circ}$
$T =\frac{2 u \sin 30^{\circ}}{ g }=\frac{ u }{ g }$
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