Answer
(a) $0.371c$
(b) $0.454c$
(c) $0.922c$
Work Step by Step
(a) We know that
$v_{21}=\frac{v_{23}-v_{13}}{1-\frac{v_{23}v_{13}}{c^2}}$
We plug in the known values to obtain:
$v_{21}=\frac{0-(-0.371c)}{1-0}$
$\implies v_{21}=0.371c$
(b) We know that
$v_{21}=\frac{v_{23}-v_{13}}{1-\frac{v_{23}-v_{13}}{c^2}}$
We plug in the known values to obtain:
$v_{21}=\frac{0.100c-(-0.371c)}{1-\frac{(0.100c)(-0.371c)}{c^2}}$
This simplifies to:
$v_{21}=0.454c$
(c) We know that
$v_{23}=\frac{v_{21}+v_{13}}{1+\frac{v_{13}v_{21}}{c^2}}$
We plug in the known values to obtain:
$v_{23}=\frac{0.454c+0.806c}{1+\frac{(0.454c)(0.806c)}{c^2}}$
$\implies v_{23}=0.922c$
