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​The greater the distance traveled by an object in a given time, the greater is its average speed. A car that has traveled 80 km in one hour has lower average speed than an airplane covering 800 km in one hour. In either case, however, it is unlikely that a constant speed was maintained for one hour. The car may have to slow down on curves or hills or to stop for red lights or crossings; conversely, it may have picked up speed on open stretches and while overtaking other vehicles. Hence, we say the car has an average speed of 80 kilometers per hour.

​Speed

​is the rate at which distance is covered over time. (Scalar quantity-only tells the magnitude)

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average speed = 

total distance traveled /

elapsed time

Average speed is the rate at which total distance traveled varies with the total time taken.

​instantaneous speed

​Speed at an instant or at a point on the path.

​The speed that you see in the speedometer is an instantaneous speed.

​Velocity

​refers to the direction associated with speed

​Average Velocity

The average velocity of a moving body is defined as the displacement divided by the elapsed time:

​Calculating Velocity

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​Pause

​Go to your textbook and review sample question about velocity:

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​Nilo drives his van with an average velocity of 45.0 km/h along the North Expressway. How long will it take him to drive 350 km on a perfectly straight highway?

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​When done. Procedd to the next slide.

Lesson ends here​

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