Vi = 30 m /sec
Vf = 0 ( at max. height)
g = - 9.8 m/ sq. sec. ( -ve sign shows that the motion of the body is in opposite direction to that of gravity)
Height it gains=h = ?
Using 3rd equation of kinematics,
2ah=Vf ˄2 – Vi˄2
implies that
h = Vf ˄2 – Vi˄2 / 2a
h = 0˄2 - (30)˄2 / 2(-9.8) = - 900/ -19.6
h = 45.91 m
So the maximum height the body can gain is approximately equal to 46 m.
Note: in simple approximation if we take g = 10 m/ sq.sec then the max. height the body can attain will be 45 m.
