Physics

Problem

A projectile is fired with speed

u

at an angle

\theta

to the horizontal. Derive an expression for the time

t

at which the velocity vector of the projectile becomes perpendicular its initial velocity vector. Will it be valid for all values of

\theta

? Calculate the ratio of the initial Kinetic Energy (

K_{0}

) to the Kinetic Energy at time

t

(

K_{t}