Question

Manny is repairing a window air conditioning unit on the 11th floor of a building and is approximately 98 off the ground. While working, Manny drops his screwdriver. The height (h) of the screwdriver in feet after t secounds of falling from the 11th floor is modeled by the function h= -16^2 + 98. How long will it take for the screwdriver to reach the ground? Round to the nearest tenth if neccesary.​

Answer 1

`t=2.5\ seconds`

Explanation:

we have

`h=-16t^(2) +98`

To find out how long it will take for the screwdriver to reach the ground, find the t-intercept of the function

Remember that

The t-intercept of the function is the value of t when the value of function h(t) is equal to zero

so

equate the function h(t) to zero and solve the quadratic equation

`-16t^(2) +98=0`

Solve for t

`16t^(2)=98`

Divide by 16 both sides

`t^(2)=6.125`

square root both sides

`t=2.5\ seconds`