An airplane has a mass of 8,000 kg and is flying at 150 m/s in level flight. The airplane drops 1,000 kg of water on a fire below. The speed of the airplane after dropping the water is
A) 50 m/s.
B) 60 m/s.
C) 75 m/s.
D) 100 m/s.
E) 150 m/s.

Question

Quizplus · Accepted Answer

The speed of the airplane remains the same (150 m/s) after dropping the water because dropping mass in a frictionless environment (assuming no air resistance for this theoretical physics problem) does not change the velocity of the airplane. This is an application of the conservation of momentum, where the total momentum before the event (mass x velocity) is equal to the total momentum after the event, assuming no external forces act on the system.

An Airplane Has a Mass of 8,000 Kg and Is