Why is speed called a scalar quantity?
It has magnitude but no direction
Physical quantities are classed by whether describing them needs direction as well as size; this distinction separates scalars from vectors.
A scalar quantity is completely specified by its magnitude alone, whereas a vector needs both a magnitude and a direction to be fully defined.
Speed measures only how fast an object is moving, for example in kilometres per hour, and says nothing about which way it goes.
Because speed carries magnitude but no direction, it fits the definition of a scalar exactly.
Velocity is the related vector: it is speed together with direction, which is why velocity can change even when speed stays constant.
Speed does not act opposite to motion, depend only on force, or change with acceleration only; those statements misdescribe it, so they are incorrect.
Hence, the answer is It has magnitude but no direction.
Similar Questions
Which of the following statements correctly describes average velocity and its SI unit?
A car travels on a highway, and its odometer records a reading of 180 km at 8:00 am and 240 km at 9:30 am. Based on this information, which statement best describes the car's average speed during this interval?
A car travels 90 km east and then 30 km west along the same straight road. If the entire journey takes 3 hours, what is the average velocity of the car?
A car travels 60 km north in 2 hours, then 40 km south in the next 1 hour. What is the car’s average velocity over the entire trip?
Which of the following best describes the function of a speedometer in a vehicle?
A cyclist travels 120 km in 3 hours, rests for 1 hour, and then travels another 80 km in 2 hours. To determine the cyclist's average speed for the entire journey, which of the following quantities should be used?
A cyclist rides 60 meters north, then 80 meters south, and finally 70 meters north. What is the total distance the cyclist has traveled?
A car travels from point A to point B in a zigzag path, covering a total distance of 200 meters. If the shortest straight-line distance between A and B is 120 meters, which statement best describes the car’s distance and displacement?
Important Questions from Speed and Velocity
The basic unit of speed of an object is ______.
Which of the following quantities specifies its speed with direction?
- Which of the following represents non-uniform linear velocity?
- Which of the following describes the nature of the average speed?
- An object moving at 25 m/s is brought to rest in 5 seconds. The final velocity is _________.
