<em><u>Average Speed</u></em>
Jack swims nine lengths of a 25 meter long swimming pool in 2 minutes and 32.1 seconds.
So, total distance
and time ![=(60*2+32.1)seconds=152.1 seconds](https://tex.z-dn.net/?f=%3D%2860%2A2%2B32.1%29seconds%3D152.1%20seconds)
Thus, average speed of Jack ![=\frac{Distance}{Time}=\frac{225}{152.1}meters/second=1.4792...meters/second](https://tex.z-dn.net/?f=%3D%5Cfrac%7BDistance%7D%7BTime%7D%3D%5Cfrac%7B225%7D%7B152.1%7Dmeters%2Fsecond%3D1.4792...meters%2Fsecond)
Now, Jill swims ten lengths of the 25 meter long swimming pool in the same time interval.
So, the total distance
and time ![=152.1 seconds](https://tex.z-dn.net/?f=%3D152.1%20seconds)
Thus, average speed of Jill ![=\frac{Distance}{time}=\frac{250}{152.1} meters/second=1.6436...meters/second](https://tex.z-dn.net/?f=%3D%5Cfrac%7BDistance%7D%7Btime%7D%3D%5Cfrac%7B250%7D%7B152.1%7D%20meters%2Fsecond%3D1.6436...meters%2Fsecond)
<u><em>Average Velocity</em></u>
As Jack swims nine lengths of the pool, it means he ends up at the opposite end of the pool from where he started. So, the net displacement = 25 meter
Thus, average velocity of Jack ![=\frac{Displacement}{Time}=\frac{25}{152.1} meters/second=0.1643...meters/second](https://tex.z-dn.net/?f=%3D%5Cfrac%7BDisplacement%7D%7BTime%7D%3D%5Cfrac%7B25%7D%7B152.1%7D%20meters%2Fsecond%3D0.1643...meters%2Fsecond)
Now, Jill swims ten length of the pool, it means he ends up at the starting position. So, the net displacement = 0 meter
Thus, average velocity of Jill
meter/second.