A farmer moves along the boundary of the square feild of side 10m in 40 seconds. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds from its initial position?
Let the initial point of the farmer be point P
The distance covered by the farmer in 40 s is 4 × 10 = 40 m.
The total time given: 2 min and 20 s = (2 × 60) + 20 = 140 s
Since the farmer moves 40 m in 40 s, therefore in 1 s the farmer covers a distance,
40/40 m =1 m
Therefore, the distance covered by the farmer in 140 s is:
140 × 1 m = 140 m.
Thus the number of rotations to cover 140 m along the boundary is:
So, the farmer will be at point R after 140 s.
So the displacement = PR =
= 14.1 m