Question

in a hare totoise race the hare ran for 5 minutes at a speed of 5km/h , slept for 50 minutes , and then ran for 5 minutes at a speed of 7.5km/h . what is the average speed of hare in the race?​

Answer 1

Given data : In a hare-tortoise race the hare ran for 5 minutes at a speed of 5 km/hr , slept for 50 minutes , and then ran for 5 minutes at a speed of 7.5 km/hr.

To find : The average speed of hare in the race ?

Solution :

Here, 5 minute = 5/60 hour = 1/12 hour.

First case :

⟹1'st speed = 5 km/hr

⟹ 1'st time = 1/12 hr

⟹ 1'st distance = ?

Now by formula of speed :

⟹ speed = distance/time

⟹ 5 = distance/{1/12}

⟹ distance = 5 * 1/12

⟹ distance = 5/12 km

∴ 1'st distance = 5/12 km

Second case :

⟹ 2'cd speed = 7.5 km/hr

⟹ 2'cd time = 5/12 hr

⟹ 2'cd distance = ?

Now by formula of speed :

⟹ speed = distance/time

⟹ 7.5 = distance/{1/12}

⟹ distance = 7.5 * 1/12

⟹ distance = 7.5/12

⟹ distance = 5/8 km

∴ 2'cd distance = 5/8 km

Now,

⟹ Total distance covered by hare-tortoise = 1'st distance + 2'cd distance

⟹ Total distance covered by hare-tortoise = 5/12 + 5/8

⟹ Total distance covered by hare-tortoise = (5*8)/(12*8) + (5*12)/(8*12)

⟹ Total distance covered by hare-tortoise = 40/96 + 60/96

⟹ Total distance covered by hare-tortoise = 100/96

⟹ Total distance covered by hare-tortoise = 25/24 km

Now,

⟹ Total time taken by hare-tortoise = 1'st time + 2'cd time + slept time

⟹ Total time taken by hare-tortoise = {5 + 5 + 50 } minute

⟹ Total time taken by hare-tortoise = 60 minute

⟹ Total time taken by hare-tortoise = 1 hour

Now,

⟹ average speed = total distance/total time taken

⟹ average speed = 25/24 /( 1 )

⟹ average speed = 25/24

⟹ average speed = 1.041666667 km/hr

Answer : Hence, average speed of hare in the race is 1.041666667 km/hr.

Learn more :

An aeroplane on a runway, starts from rest and picks up a velocity of 180 km/h and takes off. In do...

https://brainly.in/question/28483579

what is distance when time is 5 sec acceleration is 4 ms square initial velocity is 20 m/s and final velocity is 40 m/s

https://brainly.in/question/34134090