Final answer:
In physics, speed and velocity have different meanings. Speed is a scalar quantity that only accounts for magnitude, while velocity is a vector quantity that includes both magnitude and direction. Instantaneous and average speed are also distinguished in physics.
Step-by-step explanation:
Speed vs Velocity
In everyday language, speed and velocity are used interchangeably, but in physics, they have different meanings. Speed is a scalar quantity that only accounts for the magnitude of an object's motion, while velocity is a vector quantity that includes both magnitude and direction. For example, if a car is moving at a speed of 60 miles per hour, it only tells us the magnitude of its motion, but if we say the car is moving at a velocity of 60 miles per hour westwards, we include both the magnitude and direction.
Instantaneous Speed vs Average Speed: In physics, we also distinguish between instantaneous speed and average speed. Instantaneous speed refers to the speed of an object at a specific moment, while average speed is calculated by dividing the total distance traveled by the elapsed time. For instance, if a car travels a total distance of 300 miles in 5 hours, its average speed would be 60 miles per hour.