Answer:
3.1 seconds
Step-by-step explanation:
The time it will hit the ground is when the height is equal to 0. So we plug in 0 in h and solve the quadratic equation for t.
[tex]-16t^2+40t+30=0[/tex]
We will use the quadratic formula [[tex]t=\frac{-b+-\sqrt{b^2-4ac} }{2a}[/tex] ] to solve this.
a is -16
b is 40 , and
c is 30.
plugging these into the formula we get:
[tex]t=\frac{-b+-\sqrt{b^2-4ac} }{2a}\\t=\frac{-40+-\sqrt{(40)^2-4(-16)(30)} }{2(-16)}\\t=\frac{-40+-\sqrt{3520} }{-32}\\t=-0.6,3.1[/tex]
Since time cannot be negative, we take t = 3.1 as the value
So it will take 3.1 seconds to hit the ground (target)
