# Question 7f704

Oct 3, 2016

7.1 years

#### Explanation:

The expression for time dilation is:

sf(t=(t_(0))/(sqrt(1-(v^2)/(c^2)))

Since 1 year elapses on the space ship this becomes:

t=(1)/(sqrt(1-((0.99c)^2)/(c^2))

$\therefore$sf(t=(1)/(sqrt(1-(0.9801cancel(c^2))/(cancel(c^2))#

$\textsf{t = 7.1}$ years.

This means that the crew have aged by 1 year while 7.1 years have passed on earth.

If they return to earth they will be younger than if they had not gone away. This is a relativistic effect and has been verified by measurement.