Question #40610

1 Answer
Jan 21, 2017

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As referred to the figure above.

Kinetic energy at point of projection #KE_"projection"=1/2m u^2#
Maximum height of the object having mass #m# will be reached when #sin theta# component of projectile's velocity becomes #0# (zero).

As such kinetic energy at this point is given by
#KE_"max height"=1/2m(ucos theta)^2#
Ratio of the two is #(KE_"max height")/(KE_"projection")=(1/2m(ucos theta)^2)/(1/2m u^2)#
#=cos^2 theta#