Given data:
* The initial horizontal velocity of the bomber is 200 m/s.
* The horizontal range of the bomb is 2828 m.
Solution:
By the kinematics equation for the horizontal motion of the bomb is,

where u is the initial horizontal velocity, a is the acceleration along the horizontal direction, t is the time taken by the bomb to reach the ground, and R is the horizontal range of the bomb,
Substituting the known values,

Thus, the time taken by the bomb to reach the ground is 14.14 seconds.
By the kinematics equation for the motion along vertical direction is,

where u_y is the vertical component of velocity, t is the time taken to reach the ground, g is the acceleration due to gravity, and h is the height of the bomb,
Substituting the known values,

Thus, the height (oof the plane (or bomb before dropping) is 979.7 meters.