1. An object has moved through a
distance. Can it have zero
displacement? If yes, support
your answer with an example.
2. 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 thefarmer at the end of 2 minutes 20seconds from his initial position?
3. Which of the following is true for
displacement?
(a) It cannot be zero.
(b) Its magnitude is greater than
the distance travelled by the
object.
Answers
Answer:
1. yes, we know that displacement is the shortest distance from the starting point to the end point. of the starting and end points are same the displacement will be zero. for example you walked from your home to school and back to home, in this situation your displacement will be zero.
2. the displacement of the farmer is 10√2 m. he walks 40 m ( perimeter of feild of side 10m) in 40 seconds. that means he walked 1 m in 1 sec. hence in 140 seconds ( 2 min 20 sec) he walked 140 m. see in the attachment if B Is the initial position and we take it as 0 m and we count 14 rounds from it around the field (140/10 as side is 10 m) we will reach point D. now the distance BD is the displacement.
3.none of them are true
♡Answer♡:-
☆ Yes, the object instead of moving through a distance can have zero displacement. Example: If an object travels from point A and reaches to the same point A, then its displacement is zero.
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☆Given side of square =10m, thus perimeter P=40m
➡️Time taken to cover the boundary of 40 m=40s
➡️Thus in 1 second, the farmer covers a distance of 1 m
➡️Now distance covered by the farmer in 2 min 20 seconds = 1×140=140m
➡️Now the total number of rotation the farmer makes to cover a distance of 140 meters = perimeter/totaldistanc=3.5
➡️At this point, the farmer is at a point say B from the origin O
➡️Thus the displacement s= √10^+10^
➡️ from Pythagoras theorem.
s=10√2 =14.14m
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☆ (a) Not true, because if the initial and final position of the object is the same displacement can become zero.
(b) Not true, because, displacement is the shortest measurable distance between the initial and final positions of an object. It cannot be greater than the magnitude of the distance travelled by an object, but it can be smaller than the magnitude of the distance travelled by an object or , it may be equal to the distance travelled by the object.