Speed and velocity
Speed and velocity
(OP)
In Physics and Mechanics, although both refer to rapidity, and rate of change of position, is there a real difference between these two words ? For example, speed -without regard to direction- could be interpreted as the magnitude of the velocity vector which has direction and magnitude. Any comments ?





RE: Speed and velocity
RE: Speed and velocity
RE: Speed and velocity
speed is the scalar of velocity (which is a vector)
RE: Speed and velocity
RE: Speed and velocity
A vehicle speed is assumed to be the speed in the direction of travel. That may work to your advantage if a traffic officer measures your speed by radar. The measured speed is the speed along a line between the vehicle and the radar unit at the instant of measurement. If that direction is not identical with the direction of travel, the measured speed will be less than the actual speed in the direction of travel.
RE: Speed and velocity
Don't think I agree completely with Epoisses - If you're bothered about your chimneys, the wind direction is irrelevant (provided you've taken shelter far enough away). The damage is an outcome of the scalar quantity - the chimney won't heal itself if the wind changes direction.
A.
RE: Speed and velocity
RE: Speed and velocity
Should one say I go for holidays with a great speed?
or I go for vacations at high velocity?
or can I say: I go for holidays with a great speed at high velocity?
RE: Speed and velocity
RE: Speed and velocity
You can go for vacations with great speed at high velocity, but the police are going to be interested.
JHG
:)
RE: Speed and velocity
RE: Speed and velocity
In a scientific description it might be more appropriate to use the terms according to their scientific meanings. However, in general conversation using velocity could be for emphasis assuming the audience recognise it as mere speed!
RE: Speed and velocity
RE: Speed and velocity
Good points. There is often a very big difference in meaning of a word between the general public and the scientific community.
"*" to you both.
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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RE: Speed and velocity
We're engineers. This should be easy. If we accept sloppy use of the language then we deserve a progressive deterioration in its precision.
David
RE: Speed and velocity
RE: Speed and velocity
Edward L. Klein
Pipe Stress Engineer
Houston, Texas
"All the world is a Spring"
All opinions expressed here are my own and not my company's.
RE: Speed and velocity
rmw
RE: Speed and velocity
Were those African or European swallows?
Speaking of velocity. In rotating machinery vibration we look at displacement, velocity, and acceleration. It doesn't matter whether we're considering the direction or not, it's always called velocity, never speed.
I'm not saying that's right. But speed would sound pretty darned funny. I'm going to try it on my boss next week. The bearing housing speed increased to 0.3 inches per second. LOL!
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RE: Speed and velocity
"Can you take it up to an angular velocity of -200 pi radians per seconds about the longitudinal axis of the crankshaft, please?"
sounds much posher than
"floor it and bounce it off the rev limiter, mate"
Cheers
Greg Locock
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