In Physical quantities, the scalar counterpart of velocity is which of the following? Select the correct response:
Acceleration
Distance
Amplitude
Speed
The correct answer and explanation is:
The correct answer is Speed.
Explanation:
In physics, physical quantities are typically categorized into two types: scalars and vectors. Vectors are quantities that have both magnitude and direction, while scalars have only magnitude.
Velocity is a vector quantity because it has both magnitude (how fast something is moving) and direction (in which direction the object is moving).
The scalar counterpart of velocity is speed. Speed refers only to how fast an object is moving, without any consideration of the direction of motion. Speed is defined as the distance traveled per unit of time, and it does not include any directional component.
Mathematically, speed is the magnitude of velocity. If you know an object’s velocity (which has both a magnitude and direction), its speed can be found by taking the magnitude (absolute value) of the velocity vector. For example, if an object is moving at 30 m/s to the east, its velocity is 30 m/s in the eastward direction, but its speed is simply 30 m/s, with no directional information.
In contrast:
- Acceleration is a vector quantity that describes the rate of change of velocity with respect to time.
- Distance is a scalar quantity that measures the total path length traveled by an object, irrespective of the direction.
- Amplitude refers to the maximum extent of a wave or oscillation, which is also a scalar and unrelated to velocity.
Thus, the correct scalar counterpart to velocity, which measures only the magnitude of motion without direction, is speed.