A particle is projected from . the ground at an angle `theta` with the horizontal with an initial speed of ‘u’. Find the time after which velocity vector, of the projectile is perpendicular to the initial velocity

A particle is projected from the ground with a kinetic energy E at an angle of 60^(@) with the horizontal. Its kinetic energy at the highest point of its motion will be

A particle is projected at an angle theta_0 = 60^@ with horizontal, after sqrt3 seconds the angle of velocity vector with the horizontal is reduce to half of its initial value, find the speed of projection ( g = 10 m//sec^2 ).

A particle is projected with an initial velocity u, making an angle theta with the horizontal. Find the equation of the trajectory of the particle at any instant after the projection. Find expressions for the maximum height gained by the particle and its horizontal range.

A particle is projected from the surface of the earth with a speed of 20 m* s^(-1) at an angle 30^@ with the horizontal . The range of that particle is