Question

Set up an algebraic equation and then solve the following problems.

The height of a projectile launched upward at a speed of 32 feet/second from a height of 48 feet is given by the function: h(t)=-16t^2+32t+48. How long will it take the projectile to hit the ground?

Answer 1

t=-1 +square root of 2 or t=-1 - square root of 2 is the answer i think

Answer 2

3 seconds

solve for when y is zero

0 = -16t^2 + 32t + 48

0 = -16(x^2-2x-3)

0 = -16(x-3)(x+2)

x = 3 or -2

-2 is extraneous because time is not negative in this instance so 3 seconds.