Consider a rocket which has two combustion rates, (mu) 1 = 4 kg / s and (mu) 2 =
ID: 2117768 • Letter: C
Question
Consider a rocket which has two combustion rates, (mu)1 = 4 kg/s and (mu)2 = 8 kg/s. The relative speed of the exhaust gas is 90 m/s in either case.
The rocket starts from rest, in empty space. The initial mass is m0 = 4000 kg, of which 3000 kg is fuel. For time t from 0 to 250 s, the rocket runs at combustion rate (mu)1. Then for time t from 250 s to 500 s, the rocket runs with combustion rate (mu)2.
(A) Determine the final speed of the rocket.
(B) Plot an accurate graph of velocity as a function of time. Make the graph by hand and use graph paper.
*(mu)= Greek letter