Question

a farmer moves along the boundary of a square field of side 20 in 100 seconds find its speed what will be the magnitude of displacement of the farmer at the end of 3 minutes 20 seconds from his initial position​

Answer 1

Answer:

• Speed of the farmer = ⅘ m/sec
• displacement = 0

Explanation:

Given,

Side of a square field is 20metres

The farmer takes 100 seconds to complete one round.

Then,

Speed of the farmer is = distance/time.

Where,

the distance wil be the perimeter of a square field = 4 × side

= 4 × 20

= 80 metres.

∴ Speed of the farmer = 80/100 = ⅘m/sec

∴ Speed of the farmer = 80/100 = ⅘m/sec Now,

The farmer walks again for 3 min and 20 seconds or, 200 seconds

Distance covered in 200 seconds is

= speed × time

= ⅘ × 200

= 160 metres.

So, number of round completed is,

= total distance/perimeter

= 160/80

= 2 rounds.

If the farmer starts from point O after two rounds he'll reach the same points again.

∴ The displacement will be zero.

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