a farmer moves along the boundary of the square field of side 10 m in 40 seconds what will be the magnitude of the at the end of 2 metre into second
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Correct Question
A farmer moves along the boundary of the square field of side 10 m in 40 seconds what will be the magnitude of the at the end of 2 metre in 20 second.
Solution
A farmer moves along the boundary of a square field of side 10 m in 40 sec.
Side of square = 10 m and time = 40 sec
Perimeter of square = 4 × side
= 4 × 10 = 40 m
We have to find the displacement of the farmer at the end of 2 min 20 sec.
Time = 2 min 20 sec
1 min = 60 sec
2 min = 2(60) = 120 sec
= 120 sec + 20 sec = 140 sec
Now,
In 1 sec distance covered by farmer = 40/40 = 1 m
So, in 140 sec distance covered by farmer = 1 × 140 = 140 m
Number of rotations to cover 140 m along the boundary = Distance/Perimeter
= 140/40 = 3.5 rounds
Therefore, the farmer takes 3.5 revolutions.
Let us assume that farmer is at the point A from the origin of the square field.
Now,
Displacement = diagonal of square
And from above we have a side of square = 10 m
So, displacement = 10√2 m
a farmer moves along the boundary of the square field of side 10 m in 40 seconds what will be the magnitude of the displacement of farmer at the end of 2 minute 20 seconds from his initial position.
- side = 10 m
- he complete one round in 40 sec
we have to find displacement after 2 min 40 sec
or 140 seconds
as he complete one round in 40 sec
no of rounds covered in 140 seconds = 140/40=3.5
so motion is this
he cover 3 rounds and a half round.He start from a point or corner of square and at end he will be at a opposite corner . since we have to find Magnitude .
Magnitude of displacement is distance between initial and final position
use Pythagores theroem
displacement =
= 10 m