The difference between speed and velocity?

Answer 1

Speed is a scalar quantity and thus a general term; if a car is traveling at 60 mph that is its speed;

Velocity is a vector quantity that has speed and direction associated with it. If a car is traveling at 60 mph due east that is its velocity.

The two terms are often used interchangeably.

Answer 2

Speed is what is known as a scalar quantity. This means that speed is always given as a positive number or as magnitude only. Speed comes in units of distance per unit of time, and something like 50 miles per hour is a common example.

Velocity has to measured in a given direction, and it is a vector quantity. Another way to look at velocity is speed in a given direction. Because direction is important in velocity, a positive number is used to represent a forward motion and a negative number is used to represent a motion in the opposite direction. Extending the example from above, 50 miles per hour east could be a measure of velocity (as it has the direction associated with it).

To summarize, velocity is a vector, and it must have botha magnitude and a direction. Speed is just the magnitude element of the velocity.

HINT: A simple way to tell which graph is which is to check for negative values on the y-axis (values in the 3rd and 4th quadrant). Where negative values occur, the graph must be a velocity-time graph rather than a speed-time graph. Additionally, inspect the units assigned to the two axes. The time axis will be in units of time, of course, but the other axis will either be in distance only (for the speed graph), or in distance in a given direction (for the velocity graph).

Answer 3

Speed is a scalar, velocity is a vector. In other words, when a direction is important, you talk about velocity.

Speed is a scalar, velocity is a vector. In other words, when a direction is important, you talk about velocity.

Speed is a scalar, velocity is a vector. In other words, when a direction is important, you talk about velocity.

Speed is a scalar, velocity is a vector. In other words, when a direction is important, you talk about velocity.

Answer 4

Speed is a scalar, velocity is a vector. In other words, when a direction is important, you talk about velocity.