Question

A ball is thrown vertically upward from the ground. Its distance in feet from the ground in t seconds is s=−16t2+192t. After how many seconds will the ball be 560 feet from the​ ground?

Answer 1

t=7seconds or 5seconds

Explanation:

s=-16t^2 +192t

let s=560ft

560=-16t^2 +192t

16t^2 -192t+560=0

16(t^2-12t+35)=0

(t^2 -12t +35)=0

factoring it ,it will give

(t-7)(t-5)=0

solving for t

t-7=0 or t-5=0

t=7s or t=5s