We can use the kinematic equation: h = vit + 1/2g*t^2 to determine the height of an object shot upwards with an initial velocity of 120 m/s after 4.0s.
Where h is the height, vi is the initial velocity, t is the time, and g is the acceleration due to gravity (approximately 9.8 m/s^2).
h = 1204 + 1/29.8*4^2
h = 480m
The height of the object after 4.0s is 480m. So the answer is 480 m.