Obviously, we can make rockets to go very fast, but what is a reasonable top speed?
Assume that a rocket is fired from rest at a space station in deep space, where gravity is
negligible.
a) If the rocket ejects gas at a relative speed of 2000 [m⁄s
]and you want the rocket’s
speed eventually to be 1 × 10−3c, where c is the speed of light, what fraction of the
initial mass of the rocket and fuel is not fuel?
b) What is this fraction if the final speed is to be 3000 [m⁄s
]?