Question

a body is projected such that k E at thetop most position is half of intinal kE what is the angle of projection with the horizontal

Answer 1

Let Velocity at the botton be uu

Then Kinetic Energy at the bottom is KE=1/2mu2KE=1/2mu2

Now at the top only x-component of velocity is present

Let velocity at top be v

Then v=root{(ucos theta)^2}[Theta is the angle]

According to problem,

(1/2)(1/2mu^2)=1/2mv^2

=>(1/2)u^2=u^2cos^2(theta)

=>cos theta=1/root 2

theta=45 degrees

Answer 2

Explanation:

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→It is a thin and continuous layer of pollen grain which encloses the PM of a cytoplasm.

→It is made up of cellulose and pectin.

→A newly differentiate and Pollen Grain has a central nucleus and cytoplasm.