Answer:
It will take 1.12 seconds for the hammer to reach the ground.
Step-by-step explanation:
The height of the hammer after t seconds is given by the following equation:
[tex]h(t) = -16t^{2} + 20[/tex]
How long will it take the hammer to reach the ground?
This is t for which h(t) = 0. So
[tex]h(t) = -16t^{2} + 20[/tex]
[tex]-16t^{2} + 20 = 0[/tex]
[tex]16t^{2} = 20[/tex]
[tex]t^{2} = \frac{20}{16}[/tex]
[tex]t^{2} = \frac{1.25}[/tex]
[tex]t = \pm \sqrt{1.25}[/tex]
Time is a positive measure, so
[tex]t = 1.12[/tex]
It will take 1.12 seconds for the hammer to reach the ground.