Question

The speed of an athlete who has run a complete round of a circular track of radius r in time t is
a) 2nr/t c) 2nr + t
b) 2nr x t d) 2nr-t
plese answer fast and correct plese ​

Answer 1

Answer:

Option A

Explanation:

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

• The speed of an athlete who has run a complete round of a circular track of radius r in time t .

We are asked to calculate his speed.

As we know that,

➝ Speed = Distance ÷ Time

Here, we need to calculate the distance travelled first. Since, he ran on a circular track and covered one round, that means the length of the total path of the circular track will be the distance travelled. The length of the the total path of the circular track can also be considered as the perimeter of circumference of the circular track. Considering this, we can say that,

➝ Distance = Circumference of the track

➝ Distance = 2πr

• Since, the radius is r.

Now, we are given that it completes 1 round in time t . So, time taken is t .

➝ Time = t

Substitute the value of time and distance in the formula of speed.

➝ Speed = Distance ÷ Time

➝ Speed = 2πr ÷ t

➝ Speed = 2πr/t

∴ The speed of the athlete is 2πr/t.

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More Information :

• Speed is defined as distance travelled in per unit time.
• It is a scalar quantity.
• Its SI unit is m/s.
• It is denoted by v.