Question

A cyclist covers three complete Revolution on a circular track of radius 500 metre in 20 minutes find the average speed and average velocity of cyclist​

Answer 1

SoLuTioN :

➡ Given:

✏ A cyclist covers three complete revolution on a circular track of radius 500m in 20 minutes.

➡ To Find:

• Average speed
• Average velocity

➡ Concept:

✏ Average speed is defind as ratio of total distance covers to the total time and Average velocity is defind as ratio of total displacement to the total time.

➡ Conversation:

✏ 20 minutes = 1200 seconds

➡ Calculation:

• Average speed

$\implies \sf \: av.speed = \frac{total \: distance}{total \: time} \\ \\ \implies \sf \: av.speed = \frac{3 \times 2\pi \: r}{t} = \frac{3 \times 2 \times 3.14 \times 500}{1200} \\ \\ \mapsto \: \boxed{ \sf{ \red{av.speed =7.85 \: \frac{m}{s} }}}$

• Average velocity

$\implies \sf \: av.velocity = \frac{total \: displacement}{total \: time} \\ \\ \implies\sf \: av.velocity = \frac{0}{1200} \\ \\ \implies \: \boxed{ \sf{ \blue{av.velocity = 0}}}$

➡ Additional information:

• Average speed is scalar quantity whereas average velocity is vector quantity.
• Average velocity can have zero magnitude but average speed can not have zero magnitude.
• Displacement is defind as the shortest distance between two points.