A particle is moving along a circular track of radius 12 cm.

(i) What is the resultant displacement in one revolution ?

(ii) What is the distance travelled by the particle in two and a half revolutions ?

i) The resultant displacement will be zero because after one revolution the particle returns to its initial position.

ii) Here,

  r = 12 cm

 Distance travelled in 1 revolution = 2πr

Distance travelled in 2½ revolution = (5/4) × 2πr

    =  (5/4) × 2 × 22/7 × 12

    = 94.3 cm

   = 94 cm (approx)