Suppose You Stay Home on Earth While Your Twin Sister $t^{\prime}=\sqrt[t]{1-\left(\frac{v}{c}\right)^{2}}$

Essay

Suppose you stay home on Earth while your twin sister takes a trip to a distant star and back in a spaceship that travels at 99 percent of the speed of light.If both of you are 25 years old when she leaves and you are 45 years old when she returns,how old is your sister when she gets back?
Hint: Recall that the time dilation formula is:
$t^{\prime}=\sqrt[t]{1-\left(\frac{v}{c}\right)^{2}}$
where t is the time according to the person at home and is the time for the traveler.