An object is thrown directly up, starting from rest, with a velocity of 20.0 m/s and a velocity of 0 at it's peak. How high does it rise?
The equation is given by :
y = -4.9t^2 + 20t and using -b/2a ....we have the time when it reaches its max height = -20/(2* -4.9) = about 2.04 s
And the height at that time will be -4.9(2.04)^2 + 20(2.04) = about 20.4082 ft
