The University of Alabama at Birmingham (UAB)
Department of Physics
PH 462/562 – Classical Mechanics II – Spring 2006
Assignment # 2 Due: Thursday, Jan. 12
(Turn in for credit!)
1. Textbook Problem 3.5
2. Consider a rocket with initial mass m0 taking off vertically (from rest) in a
constant gravitational field g. The rocket ejects spent fuel at a constant rate
km −=
& with an exhaust speed u relative to the rocket (k is a positive constant).
a. Assuming that gravity is the only external force acting on the rocket,
derive the differential equation for its motion.
b. Solve the differential equation and determine how the height of the rocket
changes as a function of time.