Question

A football is kicked from ground level at an angle of 53 degrees. It reaches a maximum height of 7.8 meters before returning to the ground. How long will the football spend in the air, in seconds?

Answer 1

Answer:

1.61 second

Explanation:

Angle of projection, θ = 53°

maximum height, H = 7.8 m

Let T be the time taken by the ball to travel into air. It is called time of flight.

Let u be the velocity of projection.

The formula for maximum height is given by

$H = \frac{u^{2}Sin^{2}\theta }{2g}$

By substituting the values, we get

$7.8= \frac{u^{2}Sin^{2}53 }{2\times 9.8}$

u = 9.88 m/s

Use the formula for time of flight

$T = \frac{2uSin\theta }{g}$

$T = \frac{2\times 9.88\times Sin53 }{9.8}$

T = 1.61 second