posted by Alc .
a grapefruit is tossed straight up with an initial velocity of 50 ft/sec. the grapefruit is 5ft above ground when released. how high does it go before returning to the ground equation? Equation of height in terms of time y= -16t^2+50t+5
y = -16(t - 25/16)^2 + 705/16
so, the vertex is at (25/16,705/16)
That should help.