Answer:
b. He is 8 years old
Explanation:
We will use Einstein's formula for time dilation, to calculate the age of Lee. Because Lee was traveling comparable to the speed of light, his age must be lesser than Leigh.
[tex]T = \frac{T_o}{\sqrt{1-\frac{v^2}{c^2} } }[/tex]
where,
T₀ = Time on Earth = ?
T = Relative Time = 10 years
v = relativistic speed of Lee = 0.714 c
c = speed of light = 3 x 10⁸ m/s
Therefore,
[tex]10\ years = \frac{T_o}{\sqrt{1-\frac{(0.714\ c)^2}{c^2} } } \\\\[/tex]
T₀ = 7 years
Hence, the age of Lee will be:
[tex]Lee's\ Age = 1\ year + 7\ years = 8\ years[/tex]
b. He is 8 years old
