Question

A farmer moves along the boundary of a square field of side 10 m in 40 s. What will be the magnitude of displacement of the farmer at the end of 2 mins 20 secs from his initial position?

Answer 1

Answer:

10√2 m

Explanation:

Given, side of the square field = 10m

Therefore, perimeter = 10 m x 4 = 40 m

Farmer moves along the boundary in 40s.

Displacement after 2 m 20 s = 2 x 60 s + 20 s = 140 s.

Since in 40 s farmer moves 40 m

∴ in 1s distance covered by farmer  = (40/40) = 1 m

∴ in 140s distance covered by farmer = 1 * 140 = 140 m.

Now,

Number of rotation to cover 140m along the boundry  = 140/40 = 3.5 round.

Thus, after 3.5 round farmer will at point C of the field.

∴ Displacement AC = √(10)² + (10)²

                                = √100 + 100

                               = √200

                              = 10√2 m

Hope it helps!

Answer 2

$\huge\mathcal\color{teal}{Answer :- }$

Yes, an object moving a certain distance can have zero total displacement. Displacement refers to the shortest distance between the initial and the final positions of the object. Even if an object moves through a considerable distance, if it eventually comes back to its initial position, the corresponding displacement of the object would be zero.