How long will it take the object to hit the ground?

Question

The height h in feet of an object after t seconds is given by the function h=-16t^2+60t+9 How long will it take the object to hit the ground? Round your answer to the nearest thousandth.

Answer 1

the object will hit the ground when the equation = 0, aka its height is 0. -16t^2 + 60t + 9 = 0
t = -.1444, 3.9
t needs to be positive, 3.894 seconds

Answer 2

Set h = 0. Now you got a nice quadratic formula 0=-16t^2+60t+9

Answer 3

The rate the height changes in relationship to time is called velocity.
This is found by the derivative.

dh/dt= -16t+60

At its peak it velocity is zero.
Therefore at its peak;

0 = -16t+60
16t=60
t=60/16 = .375 seconds.
The time down is the same as the time up.
This comes to .750 seconds.

Answer 4

when object will hit the ground , its hight will be zero

so just solve the eqn

-16t^2+60t+9=0 for positive solution of t

t=(15+/-root (261))/8

for positive root
it is (15+root (261))/8

=3.9

Answer 5

It fairly relies upon on the burden, resistance, and gravity degrees to receive an precise prediction on how that's going to take some thing to fall. Paper will fall extra slowly than a Brick because it does no longer have a lot resistance air is pocketing below it and that's lighter. If dropped on the moon for instance it wouldtake a a lot longer time for a feather to drop because of a lot less gravity. try it out and protecting on pondering!

Answer 6

Set the equation equal to zero and solve for t