## College Physics (4th Edition)

The speed of Baker relative to the Earth observer is $0.300~c$
Let $v_{BA}$ be the velocity of Baker relative to Able. Then $v_{BA} = -0.114~c$ Let $v_{AE}$ be the velocity of Able relative to Earth. Then $v_{AE} = 0.400~c$ We can find $v_{BE}$: $v_{BE} = \frac{V_{BA}~+~v_{AE}}{1+\frac{(v_{BA})~(v_{AE})}{c^2}}$ $v_{BE} = \frac{(-0.114~c)~+~(0.400~c)}{1+\frac{(-0.114~c)~(0.400~c)}{c^2}}$ $v_{BE} = \frac{0.286~c}{0.9544}$ $v_{BE} = 0.300~c$ The velocity of Baker relative to the Earth is $0.300~c$ Therefore, the speed of Baker relative to the Earth observer is $0.300~c$.