Question

uniform speed of 240 km
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​

Answer 1

Answer:

Given,

In first event, displacement S=200m in time t

1

=25sec

In second event, displacement S=−100m in time t

1

=15sec

Average velocity=

total time

Total displacement

=

t

1

+t

2

S+(−S)

=

25+15

200+(−100)

=2.5ms

−1

Average speed=

total time

Total distance

=

t

1

+t

2

S+S

=

25+15

200+100

=10ms

−1

Hence, Average velocity 2.5ms

−1

and average speed is 10ms

−1

Explanation:

By this example you can solve this question.

Answer 2

$\bold{Answer\;:-}$

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

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