Question

An athlete completes two and half rotation in 20 seconds.Find average speed? Explain briefly please!!​

Answer 1

Answer:

• πr/4 m/s is the required answer

Explanation:

According to the Question

It is given that,

• Athlete complete two and half rotation.
• Time taken to complete the rotation ,t = 20s

we have to calculate the average speed of the athletes.

As we know that average Speed is calculated by total distance covered in total time taken.

Here, the athlete moves in circular path .

So, distance covered by athlete = 2πr

Distance covered by athlete in 2 and half rotation

= 2πr + 2πr + πr

= 5πr

Now, calculating the average Speed

• Average Speed = Total Distance/Total Time

by putting the value we get

➻ Average Speed = 5πr/20

➻ Average Speed = πr/4 m/s

• Hence, the average speed of the athlete is πr/4 m/s.

Answer 2

Answer:

• Average Speed = πr/4 units per second

Explanation:

Given,

• An athlete completes two and half rotation in 20s.

To Find,

• The average speed of athlete.

Solution,

Distance = 2 and ½ rotation of Circular path •••[Given]

• ➟ Distance = 2πr × 2 + 2πr × ½
• ➟ Distance = 4πr + πr
• ➟ Distance = 5πr

The Distance is 5πr.

The Time taken is 20s. •••[Given]

Average Speed = The rate of covering Distance

• ➟ Average Speed = s / t
• ➟ Average Speed = 5πr / 20s
• ➟ Average Speed = πr/4 units per second.

Required Answer,

• Average Speed = πr/4 units per second