Question

A soccer ball is kicked from the top of a 64 ft building into the air at an initial speed of 48 ft/sec. Its flight as a functions of time can be modeled by: h(t)=−16t2+48t+64. After how many seconds, will the soccer ball hit the ground (h=0)?

Answer 1

t = 4 seconds

Explanation:

The height of a soccer ball as a function of time is given by :

`h(t)=-16t^2+48t+64`

We need to find the time when the ball hit the ground i.e. h = 0

Put h = 0 in above equation. So,

`-16t^2+48t+64=0\\\\16(-t^2+3t+4)=0\\\\-t^2+3t+4=0`

It is a quadratic equation such that,

t = -1 s and t = 4 s

Neglecting -1 s, the ball will hit the ground after 4 seconds.