Question

an object has moved through a distance. can it have zero displacement? if yes, support your answer with an example.​

Answer 1

Answer:

First of all ,

What is the difference between distance and displacement?

The position of goes on changing with respect to time.The length of actual path covered by a body in a time-interval is called the distance, while the difference between the final and the initial position of an object is called the displacement.

The position of a body is always expressed with respect to some reference point.

Let,

Initial position = $s_{1}$

Final position =  $s_{2}$

Here, Displacement =  $s_{2}$ -  $s_{1}$

The displacement  will be positive =  if  $s_{2}$ >  $s_{1}$

The displacement  will be negative =  if  $s_{2}$ <  $s_{1}$

The displacement  will be zero =  if  $s_{2}$ = $s_{1}$

Learn through an example :

Suppose our school is at a distance of 4 km from our house.

We go to the school from our house and come back.

Although we travelled 8 km ,but our displacement remains zero, because our position has not changed.

Similarly if we throw a stone upto height $h$ , after some time it return to the same place.

Again,the displace of the stone is zero but the distance covered by it is $2h$.

Answer 2

Given that an object has moved through a distance. We are asked if the object can have a zero displacement. So, when we can have zero displacement?

1) If the object hasn't moved any distance.

2) If the object has moved through some distance, and returned to the initial point after the journey.

Here, we are said that the object has moved through some distance. Hence, the only way by which displacement can be zero is the second way.

If the object would have moved some distance, but returned at the same initial point at last, then the object would have zero displacement.

For an example, you can consider yourself. You moved 10 m distance from a point A, in your front.

Now, you just turned back, and moved 10 m. Now, you would find yourself, that you have returned to the same point A. You moved a distance of 20 m in total. But, your final and initial point is same, so you haven't done any displacement.

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JUST TO MAKE CONCEPT CLEAR (NOT RELATED TO EXAM POINT OF VIEW)  Suppose your mom is gone to market. You, watched a vase on the table. You took it with you and went into the kitchen. Grabbed some food, and left the vase there. The vase has moved some distance. Now, you remembered that the vase is in kitchen. You moved, and placed it on the table. At the same time mom arrives, she would not say where the vase is, because it's on the tale only. But, if you would have left that in kitchen, she would ask you, "Why the vase is displaced in the kitchen?"

But now, since it's not displaced for her, she won't know anything that you have moved it into the kitchen.