Distance and Displacement MCQs Quiz | Class 9
Class IX Science (Code 086) Quiz from Unit III: Motion, Force and Work. This quiz covers Distance and Displacement, focusing on Definitions, differences, and examples. Attempt the 10 multiple-choice questions below, submit to check your score, and download the answer PDF for revision.
Understanding Distance and Displacement
In the study of Motion (Class 9 Science), understanding the difference between distance and displacement is fundamental. These two quantities may seem similar but define movement in very different ways.
1. Distance
Definition: Distance is the total path length covered by an object during a given time, irrespective of direction.
- It is a scalar quantity (has only magnitude, no direction).
- It can never be zero or negative for a moving body.
- The SI unit is the meter (m).
- Example: If you walk 5 meters East and then 5 meters West, the distance traveled is 10 meters.
2. Displacement
Definition: Displacement is the shortest straight-line distance between the initial position and the final position of an object, along with direction.
- It is a vector quantity (has both magnitude and direction).
- It can be positive, negative, or zero.
- The SI unit is the meter (m).
- Example: If you walk 5 meters East and then 5 meters West (returning to the start), your displacement is 0 meters.
Key Differences
| Feature | Distance | Displacement |
|---|---|---|
| Type | Scalar | Vector |
| Value | Always Positive | Positive, Negative, or Zero |
| Path | Depends on path taken | Independent of path (Initial to Final) |
| Magnitude | Greater than or equal to displacement | Less than or equal to distance |
Quick Revision Notes
- Odometer: The device in vehicles that measures the distance traveled.
- Circular Motion: If a body completes one full circle, its distance is the circumference (2 pi r), but its displacement is zero because the start and end points are the same.
- Straight Line Motion: Only when an object moves in a straight line without changing direction, the magnitude of distance equals the magnitude of displacement.
Extra Practice Questions
- A particle moves 3 m North, then 4 m East. What is the distance? (Answer: 7 m)
- A particle moves 3 m North, then 4 m East. What is the displacement? (Answer: 5 m, calculated by Pythagoras theorem)
- Can displacement be greater than distance? (Answer: No, never)
- What is the displacement of a satellite after one orbit? (Answer: Zero)
- If a car travels 100 km and returns to the garage, what does the odometer show? (Answer: 200 km – added distance)
