A particle is projected making angle 45°with horizontal having kinetic energy K. The kinetic energy at highest point will be…

A particle is projected making angle $45^\circ$ with horizontal having kinetic energy K. The kinetic energy at highest point will be : -
A $\dfrac{K}{\sqrt{2}}$
B $\dfrac{K}{2}$
C 2K
D K

Detailed Solution

At the highest point, the vertical component of velocity is zero and only the horizontal component $u\cos\theta$ remains.
$K' = \dfrac{1}{2}m(u\cos\theta)^2 = K\cos^2\theta$
$K' = K\cos^2 45^\circ = K\left(\dfrac{1}{\sqrt{2}}\right)^2 = \dfrac{K}{2}$

Projectile Motion in past papers

12 questions from this chapter have appeared across 11 exam years.

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Practise Projectile Motion All 12 questions This chapter in 2001 AIPMT