Question

Explain this please.

Answer 1

Side of the square = 10 m

Perimeter of the square = 4X 10 = 40 m

He completes 1 round in 40 s.

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

distance covered in 2 min 20 s or 140 s is = 140 X 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.

That means if the farmer starts from point A of the square field, he reaches point C.
Therefore, displacement is AC.
Assume ABC is a right angled triangle.
Therefore,
AC2= AB2 +BC2 
AC2= (10)2 +(10)2
AC2= 100+100
AC2=200

AC = (200)1/2
 
AC= 10× (2) ½