Question

a farmer moves along the boundary of a square field of side 10 in 40 second what will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds from his initial position​

Answer 1

Answer:

$10 \sqrt{2}$

Answer 2

Answer:

10√2 = 14.14

Explanation:

Perimeter of the square field = 10 * 4 = 40

Time taken to move along perimeter = 40 sec

Time given = 2 minutes 20 sec = 120 + 20 = 140 sec

No. of rounds taken = 140/40 = 3.5 rounds

That means 3 complete rounds and one half round.

So at the end of 2 min 20 sec, the farmer is at the opposite corner of his initial position.

Since displacement is the shortest distance from initial point, we need to use Pythagoras theorem to find the length of the diagonal of the square, as it is the shortest line which connects two opposite ends of a square.

side² + side² = diagonal²

10² + 10²        = diagonal²

100 + 100      = diagonal²

200               = diagonal²

√200            = diagonal

√100 * 2       = diagonal

10√2             = diagonal

Taking the value of root 2 as 1.414,

Ans: The displacement is 14.14

Hope this helped you