Physics, asked by VaishaliJagriwal, 1 month ago

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

Answers

Answered by MystícPhoeníx
83

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.

Answered by KnightLyfe
71

Answer:

πr/4 m/s

Explanation:

As per the provided information in the given question, we have:

  • An athlete completes two and half rotation.
  • Time taken to complete the rotation= 20 sec

We've been asked to calculate the average speed of the athlete.

"Average speed" is calculated by dividing total distance by total time taken. So, in order to calculate the average speed, firstly we need to calculate the total distance travelled by the athlete.

As the athlete is covering distance in a circular tract. So, the first rotation completed by the athlete is equal to the circumference of the circle.

\odot Circumference of the circle is twice the product of pi and radius of the circle.

Now, according to the question, the athlete completes two and half round. So,

\twoheadrightarrow\quad\sf{Total\: distance=2\times 2\pi r+ \dfrac{1}{2}\times 2\pi r}

Performing division and multiplication in order to calculate the total distance.

\twoheadrightarrow\quad\sf{Total\: distance=4\pi r+ \pi r}

Performing addition.

\twoheadrightarrow\quad\sf{Total\: distance=5\pi r}

Here, we have calculated the total distance that is 5πr. Let us calculate the average speed of the athlete.

\twoheadrightarrow\quad\sf{Average\; speed=\dfrac{Total\: distance}{Total\; time}}

Equating total distance and total time in order to perform division.

\twoheadrightarrow\quad\sf{Average\; speed=\dfrac{5\pi r}{20}}

Performing division in order to calculate the average speed of the athlete.

\twoheadrightarrow\quad\underline{\boxed{\pmb{\frak{Average\: speed=\dfrac{\pi r}{4}\; m/s}}}}

❝ Therefore, average speed of the athlete is πr/4 m/s. ❞

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