In physics, speed is the measurement of how far an object travels in a given amount of time. Velocity, on the other hand, while closely related to speed, is not only the measurement of how fast an object moves but of the direction in which it is moving. That is to say, speed is the absolute value of velocity, typically measured in meters per second (m/s). Converting speed into velocity requires the knowledge of what direction an object is moving during an interval of time.

Determine the speed of an object by first measuring the distance an object has traveled from predetermined points A and B. For example, consider a car rolling forward at a constant speed for 250 meters.

Measure the amount of time it takes for the object to traverse the distance between points A and B. For example, consider the car at constant speed taking 90 seconds to roll 250 meters.

Divide the distance traveled by the amount of time taken to travel from point A to point B. For example, the speed equation for the car rolling 250 meters at constant speed for 90 seconds is: (250 meters / 90 seconds) = 2.8 m/s.

Determine the velocity by considering the direction the object moves in, relative to the observer. For example, because the car rolling at 2.8 m/s is moving forward, the velocity is +2.8 m/s. If the car had been rolling backward, velocity would equal 2.8 m/s.
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