A projectile is launched from a hole in the ground one foot deep. Its height follows the equation h=-16t^2+8t-1 . Use factoring by perfect-squares to find the time when the projectile lands back on the ground.

t=0.93 seconds or t=0.07 seconds

Step-by-step explanation:

If

The time when the projectile lands on the ground is when its height, h=0.

Using Factoring by Perfect Squares

Divide all through by the coefficient of

Next, divide the coefficient of t by 2, square it and add it to both sides.

Taking square roots of both sides

Therefore:

the answer is 62