Question

A Particle moves around a circular path of radius 21 cm. Find distance and displacement of particle after (a) Half round (b) Complete round​

Answer 1

Answer:

(a) Half round------

distance = 66 cm.

displacement = 42 cm.

(b) complete round------

distance = 132 cm.

displacement = 0

Explanation:

Circumference of the circular path

= 2πr=2×(22/7)×21= 132cm.

When it covers half the circumference

Hence distance covered = 132/2 = 66 cm.

Displacement is the length of straight line i.e. the diameter of the circle.

Hence displacement is 2×21 = 42 cm

(ii) On completion of the total circular path

the distance covered is equal to the circumference of the circle = 132 cm.

As the particle comes back to its initial position displacement is zero.

Answer 2

Answer:

distance = 132 cm. = 2πr=2×(22/7)×21= 132cm. Hence distance covered = 132/2 = 66 cm. Displacement is the length of straight line i.e. the diameter of the circle