Question 429660
Albert Einstein in his theory of relativity showed that if a person travels at
 nearly the speed of light, then time slows down significantly.
 Suppose that there are twins; one remains on Earth and the other leaves in a very fast spaceship having velocity v.
 If the twin on Earth ages T0 years, then according to Einstein the twin in the spaceship ages T years, where
T(v) = T¬0 sqrt 1-(v/c) squared
T(v) = T-0 * {{{sqrt(1-(v/c)^2)}}}
In this formula c represents the speed of light, which is 186,000 miles per second.
(a) Evaluate T when v = 0.8c (eight-tenths the speed of light) and T¬0 = 10 years. 
We can just replace v/c with .8, so we have
T(v) = 10 * {{{sqrt(1-(.8)^2)}}}
T(v) = 10 * {{{sqrt(1-.64)}}}
T(v) = 10 * {{{sqrt(.36)}}}
T(v) = 10 * .6
T(v) = 6 yrs
:
(b) Interpret your result.
"The traveling twin aged only 6 yr while the stay-home twin aged 10 yrs, but 
this would only be apparent when the traveling twin returned home"