Correct Answer : Rotation of the earth is ignored
Explanation : In order to derive the ballistic missile trajectory equations, there are two assumptions made. First is that the rotation of the earth is ignored and second is that the free-flight trajectory is assumed to be symmetrical.
Correct Answer : Option (C) : Subtracting the initial eastward velocity of launch site
Explanation : The compensation for the initial velocity is done by recognizing that the true velocity of the missile at burnout is the velocity relative to the launch site (which could be measured by radar) plus the initial eastward velocity of the launch site due to earth rotation.
Correct Answer : Option (B) : 1524 ft/s
Explanation : The Earth rotates once on its axis in 23 hours 56 min producing a surface velocity at the equator of 1524 ft/sec. The rotation is from west to east.
Correct Answer : Option (D) : Missile falls short of the target
Explanation : Speed at burnout affects range as causing down-range error. If the missile is too fast at the burnout, it overshoots and if it is too slow, the missile falls short.
