A ball is launched into the sky at 54.4 feet per second from a 268.8 meter tall building. The equation for the ball’s height, h, at time t seconds is h = -3.2t2 + 54.4t + 268.8. When will the ball strike the ground?

please help

Question

A ball is launched into the sky at 54.4 feet per second from a 268.8 meter tall building. The equation for the ball’s height, h, at time t seconds is h = -3.2t2 + 54.4t + 268.8. When will the ball strike the ground?

please help

welshfella · Answer

is that 54.4 m /sec  (not feet/sec)

heyitsjess28 · Answer

Height of ground (h) = 0

Set equation equal to zero.

$$0 =-3.2t^2 + 54.4t + 268.8$$
Now, solve for t.

You should get two answers; one negative and one positive. Since you cannot have negative time, the positive answer out of the two will be the correct one.