Suppose that you measure the length of a spaceship, at rest relative to you, to be 400 m. How long will you measure it to be if it flies past you at a speed of v

264 m

Explanation:

The complete question is

Suppose that you measure the length of a spaceship, at rest relative to you, to be 400 m. How long will you measure it to be if it flies past you at a speed of v = 0.75c

using the length contraction relationship,

where

is the relativistic length

is the actual length = 400 m

v is the velocity of the spaceship

c is the speed of light

since v = 0.75c

v/c = 0.75

substituting, we have

= 400 x 0.66 = 264 m

28. evolution

29. environment, survive, offspring  

explanation:

asthenosphere and convection