Answer:
[tex]t=2.5\ seconds[/tex]
Step-by-step explanation:
we have
[tex]h=-16t^{2} +98[/tex]
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
[tex]-16t^{2} +98=0[/tex]
Solve for t
[tex]16t^{2}=98[/tex]
Divide by 16 both sides
[tex]t^{2}=6.125[/tex]
square root both sides
[tex]t=2.5\ seconds[/tex]