The height, in feet, after x seconds of an object launched straight up can be found by the function h(x)=−16x2+v0x+h0, where v0 is the initial velocity of the object and h0 is the initial height.
a ball is kicked straight up into the air from a height of 8 ft with an initial velocity of 28 ft/s.
after how many seconds does the ball hit the ground?