Question

A baseball is thrown upward at a velocity of 36 feet per second from a height of 7 feet. The equation to represent the height (h) after t seconds is h= 1612 + 361 + 7. How long before the ball hits the ground? ​

Answer 1

about 2.43 seconds

Explanation:

You want the time when the height described by h = -16t² +36t +7 is equal to zero.

Solution

The quadratic equation ...

-16t² +36t +7 = 0

can be solved using the quadratic formula. It tells you the solution to ...

ax² +bx +c = 0 is ...

`x=(-b\pm√(b^2-4ac))/(2a)`

Then the solutions to the given quadratic are ...

`x = (-36\pm√(36^2-4(-16)(7)))/(2(-16))=(9\pm√(109))/(8)\approx\{-0.180,2.430\}`

The ball will hit the ground after about 2.43 seconds.