Question

A person was walking around a circular park of radius 2m.

a) How much distance he walks if he starts from one point round the park and stops exactly diagonally on the opposite point?

b) How much displacement he covers in this portion?

c) Out of the distance and displacement, which has direction? ​

Answer 1

Answer:

1.  An object has moved through a distance. Can it have zero displacement? If yes, support your answer with an example.

Answer: An object can have zero displacement even when it has moved a distance and shown some displacement. This takes place when the final position of an object coincides with its own initial position. Let's say, if a person moves around circular area and comes back to the place from where he started then the displacement will be zero.

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 the farmer at the end of 2 minutes 20 seconds from his initial position?

Answer:

Here, Side of the given square field = 10m

so, perimeter of a square = 4*side = 10 m * 4 = 40 m

Farmer takes 40 s to move along the boundary.

Displacement after 2 minutes 20 s = 2 * 60 s + 20 s = 140 seconds

since in 40 s farmer moves 40 m

Therefore, in 1s the distance covered by farmer = 40 / 40 m = 1m

Therefore, in 140s distance covered by farmer = 1 � 140 m = 140 m. Now, number of rotation to cover 140 along the boundary= Total Distance / Perimeter

= 140 m / 40 m = 3.5 round

Thus, after 3.5 round farmer will at point C of the field.

Thus, after 2 min 20 seconds the displacement of farmer will be equal to 14.14 m north east from initial position.