Physics, asked by InfinityIQ36, 10 months ago

I will mark as the brainliest.
A boy runs for 10 mins at a uniform speed for 9 km/h. At what speed should he run for further 20 mins, so that his average speed is 12km/h?​

Answers

Answered by pwnjangir07
0

Explanation:

ANSWER

s

1

=v

1

t

1

And, s

2

=v

2

t

2

Average speed v=

t

s

=

t

1

+t

2

s

1

+s

2

⟹v=

t

1

+t

2

v

1

t

1

+v

2

t

2

⟹v

2

=

t

2

v(t

1

+t

2

)−v

1

t

1

⟹v

2

=

20

12(10+20)−9×10

⟹v

2

=13.5km/h

Answered by kaamilahap
1

Answer:

hello

Explanation:

Boy runs for first 10 min at 9 kmph  = 9 km/hr

Let boy run for next 10 min at V kmph

let boy run for next 10 min at V kmph

His average speed is  average of above three. 

Average speed =  (9+ 2 V) / 3   =  12 kmph

So    9 + 2 V = 3 * 12 = 36

2 V = 36 - 9 = 27

V = 27/2 = 13.5 km/hr

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