ELI5: difference between speed and velocity

ELI5: difference between speed and velocity

Speed is in any direction. Velocity is in a certain direction.

Velocity is speed plus direction. 5mph is a speed 5mph west is a velocity. All velocities are speeds but not all speeds are velocities

The difference is direction. Speed starts at 0 and only goes up. That's all it is. Velocity is allowed to be negative, or provide an angle or direction in which it points and negative numbers means the opposite direction.

Velocity is a vector, it has a magnitude and direction, . Speed is a magnitude, sqrt(x\^2+y\^2+z\^2).

Good explanation. I feel like OP could’ve just done a quick google search for this and didn’t need to ask Reddit lol

This is the big difference. Once you set the frame for direction, you can have negative velocities. Or your velocity can be broken down into dimensional components, vectors at right angles to each other that sum to your final velocity.

Speed a general term for I don’t care what direction I’m going, I can how fast I’m going.

Speed is usually in most frames just the absolute value of your velocity.

Speed just says how fast you are going. Velocity also gives a direction. Speed would be saying I am going 60mph, while velocity says I am traveling 60mph north east. You can also say you are traveling -15mph in the north east direction to say you are going 15mph south west.

Usually on a coordinate graph it works just like plotting a ray.

Ones Vector ones a Scalar. This just means one knows where it's going

That’s true of literally every question on this subreddit.

ELI5 version, it's the difference between saying "I'm driving at 60 mph" (speed) and "I'm driving at 60 mph north" (velocity).

Velocity is a Latin root word that just mean speed. Then English (Germanic root) speakers borrowed the word and changed the meaning to also include direction. So in English speed means just how fast something is going and velocity also means how fast something is going and what direction is going. In Latin root languages when we want to include heading you include vectorial. Like this, vectorial velocity

You think in such three dimensional terms. How small you’ve become.