(i) Define circular motion. (ii) What is the difference between uniform motion in a straight line and … at the end of 2 min and 20…
(i) The motion of the body moving around a fixed point in a circular path.
(ii) Uniform motion in straight line
(a) The direction of motion of object does not change.
(b) If an object moves with a constant speed its accelera-tion is zero.
Uniform in circular motion
(a) Direction changes continuously.
(b) Acceleration is not zero even on moving with constant speed.
(iii) Diameter of track = 200 m
Radius = 100 m
The distance covered in
40 sec = 2πr
= 2π × 100 = 200π
The distance covered in 2 min 20 sec (140sec)
= 200 / 40 π × 140 = 700 π m
So, displacement will be 200 m
No. of complete rounds covered by athlele
700 π / 200 π =
He covers rounds.