Question

A farmer moves along the boundary of a square field of side 10m in 40s what will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds .

Answer 1

Question

A farmer moves along the boundary of a square field of side 10m in 40s what will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds .

Answer

Perimeter of square = 4s = 4*10 = 40 m

So a farmer moves 40 m in 40 s

Hence a farmer moves a meter per second .

Magnitude of displacement of the farmer at the end of 2 minutes 20 seconds : -

Time = 2 min 20 sec = 120 + 20 sec

⇒ Time = 140 sec

So After 140 sec he would be at 140 th meter . Since he moves with speed 1 m/s .

At 140 th meter he will complete 140/40 = 3.5 th round .

Displacement is defined as the shortest distance.

So the 3 rounds are not counted . Since closed .

So he will be another corner of square after half round of square ,

which resembles right angled triangle. (Find Attachment)

Now , Apply Pythagoras Theorem .

⇒ AC² = 10² + 10²

⇒ AC² = 200

⇒ AC = 10√2 m

⇒ AC = 14.4 m

Hence at the end of 2 min and 20 sec farmer's displacement is equal to 14.4 meters

Answer 2

if the farmers starts from point a then at the end of two minutes and 20seconds is equals to 140 seconds he will reach the diagonally opposite corner c the magnitude of displacement of the farmer is

if the farmers starts from point a then at the end of two minutes and 20seconds is equals to 140 seconds he will reach the diagonally opposite corner c the magnitude of displacement of the farmer isAC=√AB^2+BC^2

if the farmers starts from point a then at the end of two minutes and 20seconds is equals to 140 seconds he will reach the diagonally opposite corner c the magnitude of displacement of the farmer isAC=√AB^2+BC^2 =√10^2+10^2

if the farmers starts from point a then at the end of two minutes and 20seconds is equals to 140 seconds he will reach the diagonally opposite corner c the magnitude of displacement of the farmer isAC=√AB^2+BC^2 =√10^2+10^2=10√2

if the farmers starts from point a then at the end of two minutes and 20seconds is equals to 140 seconds he will reach the diagonally opposite corner c the magnitude of displacement of the farmer isAC=√AB^2+BC^2 =√10^2+10^2=10√2 =10×1.414=14.14m