posted by kyoya on .
For a safe re-entry into the Earth's atmosphere the pilots of a space capsule must reduce their speed from 2.6 104 m/s to 1.0 104 m/s. The rocket engine produces a backward force on the capsule of 1.7 105 N. The mass of the capsule is 3800 kg. For how long must they fire their engine? [Hint: Ignore the change in mass of the capsule due to the expulsion of exhaust gases.]