Question

A ball is thrown horizontally at a height of 1.5 meters at a velocity of 70 m/s. Assume no air resistance. How long until the ball reaches the ground?

0.25 s
0.38 s
0.55 s
0.67 s

Answer 1

`t = 0.55`

Step-by-step explanation:

Given

`Height, s = 1.5m`

`Velocity, v = 70m/s`

Required

Determine the time to hit the ground

Using free fall formula:

`S = (1)/(2)gt^2`

Take g as 9.8 and substitute value for S

`1.5 = (1)/(2) * 9.8 * t^2`

`1.5 = 4.9 * t^2`

Make t^2 the subject

`t^2 = (1.5)/(4.9)`

`t^2 = 0.30612244898`

Solve for t

`t = \sqrt{0.30612244898`

`t = 0.55` -- approximated