The difference between speed and velocity

In summary, velocity is a vector quantity that has a direction and a magnitude, while speed is a single positive number.
  • #1
DrWarezz
33
0
Hi all,
I think the title says it all :P..
What is the difference between velocity and speed? I understand that velocity is a fair bit more complicated than speed. However, I often use the word "velocity" but meaning speed.

At school, the teachers say "just assume that speed and velocity are the same" (to those few that actually know what speed is! lol :smile: ).

So; what's the difference? :shy:

Thanks in advance.. :)
[r.D]
 
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  • #2
Velocity has a DIRECTION as well as a MAGNITUDE (that is, velocity is a VECTOR quantity if you've learned that term yet)
The magnitude of velocity is called SPEED (just a POSITIVE number/scalar, not a vector)
 
  • #3
Hello!
There is a little difference between two concepts: velocity and speed. First of all, let's regard that you are at axis-x, to 3 meters from origin of cartesians system, so you walk to origin. Later, you walk again more 4 meters at axis-y. So, your displacement is 5 meters, according Pitagoras' theorem, but, the distance that you've covered is 7 meters. In others terms, the displacement is a vector, then, depend only two points( at this case is final point minus initial point). The distance is what you really walked. Therefore the velocity is the time variation of displacement and the speed is the time variation of distance.
 
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  • #4
Every work day, I leave my home to drive to my work which is 20km West. When I am on the highway I set my cruise control to 100km/hr. That is my speed it is the same both on my way to work and on my way home. My velocity however is different in the morning then in the evening. In the morning my velocity is 100 km/h EAST, in the evening it is 100 km/h WEST. Thus it requires 2 numbers to specify velocity, it is possible to have a negative velocity. Speed on the other hand is a single positive number.

Edit to avoid confusion, I work at night!
 

FAQ: The difference between speed and velocity

What is the difference between speed and velocity?

Speed is a measure of how fast an object is moving, while velocity is a measure of how fast an object is moving in a specific direction.

How are speed and velocity related?

Speed and velocity are both measures of an object's motion, with velocity being a more specific measure that takes into account both the magnitude and direction of the movement.

Can an object's speed be greater than its velocity?

Yes, an object's speed can be greater than its velocity if the object is moving in a curved path, such as a circle. In this case, the object's speed may be constant, but its velocity is constantly changing as it moves in different directions.

Which is more important in determining an object's motion, speed or velocity?

Both speed and velocity are important in determining an object's motion. While speed tells us how fast an object is moving, velocity also includes information about the direction of the movement, which is crucial in understanding an object's overall motion.

How is speed different from average speed?

Speed is a measure of how fast an object is moving at a specific moment, while average speed is the total distance traveled divided by the total time taken to travel that distance. Average speed takes into account the entire journey, while speed only looks at a specific moment in time.

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