how do I solve this

Question

If you throw a ball straight up into the air with a velocity of 50 ft/s from an initial height of 5 ft, the quadratic equation that models the height h after t seconds is h(t) = −16t² + 50t + 5.

After how many seconds will the ball hit the ground?

Answer 1

Set h(t)=0 and solve the resulting quadratic equation for t. You will get a positive solution and a negative solution. Since time starts at t=0, the positive solution is the correct one.