Difference between Speed and Velocity in Class 9th
In physics, speed and velocity are two important terms that are commonly used interchangeably. However, there is a fundamental difference between these two terms that students of Class 9th should be aware of.
What is Speed?
Speed is defined as the rate at which an object covers a distance. It is a scalar quantity that is measured in units of distance per unit time, such as meters per second or kilometers per hour. The speed of an object is always positive, and it only tells us the magnitude of the motion, not its direction. For example, if a car travels 100km in 2 hours, its speed is 50 km/hour.
What is Velocity?
Velocity, on the other hand, is defined as the rate at which an object changes its position with respect to time. While velocity also involves the concept of distance and time, it is a vector quantity that takes into account both the magnitude and direction of the motion. Velocity is measured in units of distance per unit time, such as meters per second or kilometers per hour, and it is always represented by a direction. For example, if a car travels 100km in 2 hours northwards, its velocity is 50 km/hour northwards.
The Key Difference between Speed and Velocity
The key difference between speed and velocity is that the former only gives the magnitude of the motion, while the latter takes into account the direction of the motion. In other words, while speed is a scalar quantity, velocity is a vector quantity.
In conclusion, speed and velocity are two important concepts that students of Class 9th need to understand. While they both involve the concepts of distance and time, speed is simply the rate at which an object covers a distance, whereas velocity takes into account both the magnitude and direction of an object’s motion.
Table difference between speed and velocity in class 9th
| Speed | Velocity |
|---|---|
| Refers to the distance traveled by an object in a certain time. | Refers to the displacement of an object in a certain time. |
| Does not take direction into account. | Takes direction into account. |
| Scalar quantity | Vector quantity |
| Example: A car traveled 50 km/h. | Example: A car traveled 50 km/h to the east. |