Given:-

Bhuvi jogs a circular ground of  diameter 14 km

To Find:-

the distance and  DISPLACEMENT covered by her in

a. 3 rounds

b. 2 1/2 rounds

c 4 1/4 rounds

d. 1 3/4 rounds

Solution:-

Radius (r) = diameter/2 = 14/2 = 7 km

a. 3 rounds-

Distance covered in 1 round = 2πr = 2x22/7x7 = 44 km

Distance covered in 3 rounds = 3 x 44 = 132 km

Displacement is the shortest distance between the initial and the final position

Displacement covered in 3 rounds = 0 (Since the initial position coincides with the final position)

b. 2 1/2 rounds

Distance covered = 2.5 x distance covered in 1 round = 2.5 x 44 = 110 km

In 2.5 rounds, Bhuvi will REACH the other END of the semicircular path

⇒ Displacement =2r = 14 km

Hence the distance and displacement covered at the end of 21/2 rounds is 110 km and 14 km respectively.

c. 4 1/4 rounds-

Distance covered = (4 x distance covered in 1 round + 1/4 x distance covered in one round) = (4x44 + 1/4 x 44) =187 km

Displacement covered = = 7 km

hence, the distance and displacement covered at the end of 4 1/4 rounds is 187 km and 7 km respectively.

d. 1 3/4 rounds

Distance covered = (Distance covered in one round + 3/4x distance covered in one round)

= (44+ 33) = 77km

Displacement covered = r = 7

Hence, the distance and displacement covered at the end of 1 3/4 rounds is 77 km and 7 km respectively