Question

Give an example of a situation in which distance is equal to displacement.

Answer 1

Hint: To solve our problem, we should first understand the fact that distance and displacement are two different quantities. The distance travelled by a body is the sum of all lengths that the body has covered in its time duration of motion whereas displacement is the smallest distance from the point of start to the point where the motion stopped, that is, the shortest line joining these two points.

Complete answer:
Since it is a conceptual question, it should be clear that:
As long as an object is undergoing linear translation in one direction only, the displacement and the distance covered by the object will be equal. Such a motion can be represented by a straight-line equation:
$\Rightarrow Ax+By+C=0$
For example, when a ball is thrown vertically upwards then up to its maximum height, the distance and displacement of the ball are the same. Or, let us consider a car moving on a straight road. As long as the road is straight the car is bound to move in one direction only, hence the distance travelled will be equal to displacement of the car from the starting point.
In this type of motion, the acceleration could be a constant or a variable but it cannot change its sign as this could eventually change the direction of motion of the object like in the case of a Simple Harmonic Motion.

Note:
It should be noted that displacement of an object is a vector quantity and distance travelled by the object is a scalar quantity. So, when we say the distance is equal to displacement, we mean the magnitude of displacement is equal to the distance travelled by the object.