Question

2. A boy runs first 100 m with a uniform speed of 8 m/s and the next 200 m with a uniform
speed of 5 m/s. Calculate the average speed of the boy.
15.71 m/s​

Answer 1

$\bold{Answer\;:-}$

Given :-

• Distance travelled, s1 = 100 m

• Speed, v1 = 8 m/s

• Time taken to cover the distance, t1 = ?

By using the formula,

• t1 = 100/8

• t1 = 12.5 s

• Distance travelled, s2 = 200 m

• Speed, v2 = 5 m/s

• Time taken to cover the distance, t2 = ?

By using the formula,

• t2 = 200/5

• t2 = 40 s

Total distance covered, s = 100+200 = 300 m

Total time taken, t = 12.5+40 = 52.5 s

• Average speed, v(av) = s/t

• v(av) = 300/52.5

• v(av) = 5.71

$\bold{Hope\;it \; helps\;!}$