A coin is dropped from a height of 750 feet. The height, *s* (ft), at time *t* (sec), is given by s=-16t^2+750s=16t2+750. How long does it take for the coin to hit the ground?

& what is the velocity when the coin hits the ground?

1 Answer
Nov 1, 2016

6.856.85sec

Explanation:

At ground level, s=0s=0

s=0 => -16t^2+750 = 0 s=016t2+750=0
:. 16t^2 = 750
:. t^2 = 750/16
:. t^2 = 375/8
:. t = +-sqrt(375/8)
:. t = +-6.85 (2dp)

We need t>0 , and so t=6.85s (2dp)