Answer:
907.80 y
Explanation:
Given :
The speed of the astronaut is v = 0.9900 c
The time spend by the astronaut is [tex]$t_0 $[/tex] = 128 years
Therefore, the time of dilation is given by
[tex]$t=\frac{t_0}{\sqrt{1-\left(\frac{v}{c}\right)^2}}$[/tex]
[tex]$t=\frac{128 \ y}{\sqrt{1-\left(\frac{0.9900 \ c}{c}\right)^2}}$[/tex]
[tex]$t=\frac{128 \ y}{\sqrt{1-0.9801}}$[/tex]
[tex]$t = \frac{128}{\sqrt{0.0199}}$[/tex]
[tex]$t = \frac{128}{0.141}}$[/tex]
[tex]$t= 907.80 \ y$[/tex]