A NASA explorer spacecraft with a mass of 1,000 kg takes off in a positive direction from a stationary asteroid.If the velocity of the spacecraft is 250 m/s and the asteroid is pushed back –25 m/s, what is the mass of the asteroid? Assume there is no net force on the system.

With no net external force, momentum is conserved. The system starts at rest, so its total momentum is zero: (1,000 kg)(250 m/s) + M(−25 m/s) = 0. Solving gives M = 250,000 ÷ 25 = 10,000 kg, so the asteroid’s mass is 10,000 kg.

AI-written and checked against the verified answer.