Question

A cyclist moving on a circular track of radius 100m to complete one revolution in4min. find average speed and velocity

Answer 1

The total length of the circular track = 2πr = 2π(100) = 200π metres

Total time taken = 4 minutes = 240 seconds

Average speed = distance/time = 200π/240 = 5π/6 m/s = 2.6 m/s

Average velocity = displacement/time = 0/240 = 0 m/s

Therefore the average speed is 2.6 m/s and average velocity is 0 m/s.

Hope it helps!!

Answer 2

Given:

• Radius of track = 100 m
• Time taken for 1 revolution is 4 minutes

To find:

• Average speed and velocity ?

Calculation:

• Average speed is defined as the total distance divided by total time taken.

• Similarly, average velocity is defined as the total displacement divided by the total time.

For average speed :

$avg. \: v = \dfrac{2\pi r}{t}$

$\implies avg. \: v = \dfrac{2\pi \times 0.1}{ \dfrac{4}{60} }$

$\implies avg. \: v = 9.42 \: km/hr$

So, average speed is 9.42 km/hr

• Now, displacement for a full revolution is zero because starting and stopping point is same.

Hence , average velocity is zero.