# What does quantities and dimensions mean?

1. Jan 29, 2007

### elton_fan

i would like to ask a question about what does quantities and dimension mean in this sentence
is it possible for two quantities to have the same dimensions but different units?

thanks a lot in advance

2. Jan 29, 2007

A physical quantity is something that can be measured, for example, velocity, force, etc. The quantity is expressed in units, which are not to be confused with the term 'dimension'. The term 'dimension' needn't be used, actually.

3. Jan 29, 2007

### chroot

Staff Emeritus
"Length" is an example of a dimension. The "meter" is an example of a unit, one that can be used to express lengths.

- Warren

4. Jan 29, 2007

### elton_fan

so for example what would be the answer of this question?
i think it's yes
it's true

Last edited: Jan 29, 2007
5. Jan 29, 2007

### Staff: Mentor

I'll answer your question with a question. How tall are you in inches? How tall are you in centimeters? Your height dimension is the same, no matter what units you use to express that height.

Think of a particular shipping box. It has linear dimensions of length, width and height. And those dimensions can be measured using various unit systems.

6. Jan 29, 2007

### elton_fan

thanks a lot i understand now