Question

A ball is projected with velocity 10m/s at an angle of 30 degrees with the horizontal surface . The time taken by the ball to reach the ground is ... g=10

Answer 1

The ball's vertical position in the air is given by

`y=10\cos30^\circ\,t-\fracg2t^2`

and it will reach the ground at
`t` for which
`y=0`:

`0=5\sqrt3\,t-5t^2=5t(\sqrt 3-t)\implies t=\sqrt3\approx1.73`