In 1865, Jules Verne suggested sending people to the Moon by launching a space capsule with a 228.8 m long cannon. The final speed of the capsule must reach 11.39 km/s. What acceleration would the passengers experience?

Answer 1

Acceleration a from rest over a distance of S to a velocity of v is given by:
v²=2aS
or
v=11390 m/s
S=228.8m
a=v²/(2S)
=11390²/(2*228.8) m/s²
=283,505 m/s²
=28,929 g

Jules Verne had correctly calculated the escape velocity on planet earth, which is the velocity required for an object to leave earth's gravitation system without further propulson.

However, his suggestion did not include cases where propulsion could be continuous, in which case the acceleration can be much reduced.