Jan made a diagram to compare speed and velocity.
Which label belongs in the area marked X?
Is always constant
Includes magnitude
Has direction
Depends on a reference frame
The Correct Answer and Explanation is :
The correct label for the area marked “X” is “Includes magnitude”.
Explanation:
In physics, speed and velocity are two related but distinct concepts. Speed refers to how fast an object is moving, while velocity describes the speed of an object in a specific direction.
Speed is a scalar quantity, meaning it only has magnitude (how much or how fast), and does not include any information about the direction of motion. For example, if a car is traveling at 60 miles per hour, this is a speed—it tells us the rate of movement but not the direction.
On the other hand, velocity is a vector quantity, meaning it includes both magnitude (the speed) and direction. So, if the car is moving at 60 miles per hour to the north, this is the car’s velocity—it tells us both how fast the car is moving and which direction it is traveling in. Therefore, velocity depends on both the magnitude (the speed) and the direction of motion.
Labeling in the Diagram:
- The area marked “X” refers to speed, which is a scalar quantity. Since speed only has magnitude, it is labeled “Includes magnitude”.
- Velocity, on the other hand, includes both magnitude and direction. The label for velocity might say “Has direction” or “Depends on a reference frame,” as these are key characteristics of velocity.
In this case, the distinction between scalar (speed) and vector (velocity) quantities is important. Speed does not have a directional component and is simply the rate at which an object covers distance, so it “includes magnitude” as its defining feature.