Question

A child moving on a circular motion track of radius 40 m completes one revolution in 5 min? What is average speed and average velocity of child

Answer 1

Given :-

▪ A child is moving on a circular motion track of radius 40 m and he completes one revolution of that circular track in 5 minutes.

To Find :-

▪ Average speed

▪ Average velocity

Solution :-

We know Displacement is the shortest path length between final and initial position. Also, Average velocity is equal to Total displacement over Total time taken. Here, child completes one revolution which means the displacement is 0 m as he ended up at the same point he started from.

So, We have

⇒ Average velocity = 0 m/s.

For finding Average speed, we need total distance travelled i.e., circumference of the circle.

and the total time taken is already given as 5 minutes or 300 seconds because 1 minute has 60 seconds.

We know,

⇒ Circumference = 2πr

Where, r = radius of circle

⇒ Circumference = 2 × 22/7 × 40

⇒ Circumference = 44 × 5.71

⇒ Circumference = 251.24 m

So,

⇒ Average Speed = Circumference / Time taken

⇒ Avg. speed = 251.24 / 300

⇒ Avg. speed = 0.83 m/s

Hence, the average speed of the child is

0.83 m/s while the average velocity is 0 m/s.

Answer 2

Answer:

In half revolution

Displacement=diameter of circular track

=80m

∣average velocity∣=

time taken

∣Dispalcement∣

V

avg

=

40

80

=2m/s

solution

Explanation:

I hope this will helps u.i am in 8th now

thanks for reading and giving me a change to ans.u