Question

a person swims 100 m in the first 40s, 80 m in the next 40 s and 45 m in the last 20s, what is the average speed

Answer 1

Explanation:

to find:

average speed

solution:

distance he traveled first=100m

time taken by him =40sec

/

$\frac{distance}{time}$

$= > \frac{100}{40}$

$= \frac{25}{10}$

$= 2.5m /sec$

his speed of first=2.5m/sec

distance he traveled second=80m

time taken by him =40sec

his speed=

$\frac{80}{40}$

$= 2m/sec</p><p>$

his speed of second=2m/sec

distance he traveled third = 45m

time taken by him=20sec

his speed=

$\frac{45}{20}$

$= \frac{9}{4}$

$= 2.25m/sec$

his speed=2.25m/sec

average speed=

$average \: speed= \frac{100 + 80 + 45}{40 + 40 + 25} km/sec</p><p>$

$= \frac{225}{100}$

$= 2.25m \: per \: sec$