## College Physics (4th Edition)

(a) The average speed is $1.74~m/s$ (b) The average velocity is $0.332~m/s$
(a) We can find the time it takes to swim the first $50.0~m$: $t = \frac{d}{v} = \frac{50.0~m}{1.84~m/s} = 27.17~s$ We can find the time it takes to swim the next $34.0~m$ in the opposite direction: $t = \frac{d}{v} = \frac{34.0~m}{1.62~m/s} = 20.99~s$ We can find the average speed: $average~speed = \frac{distance}{time}$ $average~speed = \frac{50.0~m+34.0~m}{27.17~s+20.99~s}$ $average~speed = 1.74~m/s$ The average speed is $1.74~m/s$ (b) We can find the average velocity: $average~velocity = \frac{displacement}{time}$ $average~velocity = \frac{50.0~m-34.0~m}{27.17~s+20.99~s}$ $average~velocity = 0.332~m/s$ The average velocity is $0.332~m/s$