A runner completes one round of a circular path of radius r in 40sec. His displacement after 2 minutes 20 seconds will be
Answers
Answered by
36
Radius is r. Circumference is = 2 pi r.
Time is 40 s.
Every 40 seconds he comes back to original position l. So in 140 s he would cover 3 and half circles. Hence
Total distance is 2r pi x 3.5 = 7r pi.
Total displacement will be = 2r since ball will be directly across the diameter .
Time is 40 s.
Every 40 seconds he comes back to original position l. So in 140 s he would cover 3 and half circles. Hence
Total distance is 2r pi x 3.5 = 7r pi.
Total displacement will be = 2r since ball will be directly across the diameter .
deepanshi15:
How
Answered by
65
The runner complete one round = 40 seconds
Now, he runs for 2 mins 20 s
Convert 2 mins 2 s into seconds =
2 × 60 seconds + 20 s
= 120 s + 20 s => 140 s
Now, rounds taken by the runner = 140 / 40
=> 3.5 rounds.
Now, please see the attachment
Lets think that we started from A
1. Take 3 rounds.
2. You will surely standing on A only.
3. Now take 0.5 round and you will cover half of circle.
Hence, displacement is diameter of circle.
As, radius was r so diameter will be 2r
Have greay future ahead!
Attachments:
Similar questions