CBSE Class 9 Answered

Side of the square = 10 m

Perimeter of the square = 4×10 = 40 m

He completes 1 round in 40 s.

So, speed = 40/40 = 1 m/s

So, distance covered in 2 min 20 s or 140 s is = 140 × 1 = 140 m

Number of rounds of the square completed in moving through 140 m is = 140/40 = 3.5

In 3 rounds the displacement is zero. In 0.5 round the farmer reaches the diagonally opposite end of the square from his starting point.

Displacement = AC = (AB² + BC²)^1/2 = (100+100)^1/2 = 10?2 m