- #1

- 444

- 3

## Main Question or Discussion Point

Imagine two space ships each with thrusters that can accelerate them .1c or .3c almost instantly. The velocity addition formula indicates that if one space ship applied the .1c thruster 3 times then if c is estimated to be 300,000,000 m/s the velocity of the ship after the accelerations the ship will be approximately 87,669,903 m/s. Which is less than the 90,000,000 m/s which would have been achieved using the .3c thruster. So does this mean that the energy needed to go .1c in space < (energy needed to go .3c in space)/3?

Also given the formula (u + v) / (1 + ((u*v)/(c*c)))

Is it saying it is more expensive to try to go .1c then .4c or .4c then .1c than go .2c then .3c or .3c then .2c (because u + v = .5c in both cases, but the u * v = .04c with the .1c and the .4c, but .06c with the .2c and the .3c) but you would achieve a higher velocity?

Also given the formula (u + v) / (1 + ((u*v)/(c*c)))

Is it saying it is more expensive to try to go .1c then .4c or .4c then .1c than go .2c then .3c or .3c then .2c (because u + v = .5c in both cases, but the u * v = .04c with the .1c and the .4c, but .06c with the .2c and the .3c) but you would achieve a higher velocity?

Last edited: