Question

A man can complete a circular path of radius 7m in every 20seconds. find the distance and displacement in 40 seconds and 1 minute 10 seconds and 2 minute 5 seconds ​

Answer 1

Answer:

1. Distance and displacement in 40 sec : 88m and 0m

2. Distance and displacement in 1 min 10 sec : 198m and 14m

Explanation:

Hey mate, here's your answer step by step :

1. In 20 sec he covers a whole circle of 7m radius ,

And here he moves around the boundary which means that the total distance he covers is the perimeter of the circle.

And in 40 sec he completes 2 rounds, that means :

2×22/7×7×2 = Distance

= 88m

Now, as he reaches back to his initial position the displacement is zero .

2. 1min = 60 sec , So 1min 10 sec is = 70 sec

Now , if we divide 70 by 20 we get 3.5

This means that he covered 3.5 of the perimeter ( boundary ) of the circle

So,

Distance = 2×22/7×7×3.5

Distance = 154.0m

Now , As he covered a half distance at the end, the shortest distance (Displacement) is the daimeter of the circle.

Which is ,

radius×2

=7×2 = 14 m

HOPE IT HELPS YOU :)