Hello I've been learning the basics of physics over the past few weeks and thought I knew what they meant when they would refer to the dimensions of something for instance if you asked me what are the dimensions of acceleration I'd say 'change in velocity/time'' or 'v2-v1/T' but I came across a page on a topic I'm not familar with 'Dimensional analysis' and they had a little quiz and said the following(adsbygoogle = window.adsbygoogle || []).push({});

1. volume = Length cubed

2. acceleration (velocity/time) = Length/Time squared

3. density (mass/volume) = Mass / Length cubed

4. force (mass × acceleration) = Mass x Length/Time squared

5. charge (current × tiime) = Current x Time

Where did they get these 'dimensions from'?

For the first one its only true for the volume of a perfect cube.

The second one it seems they are substituting length for velocity and I don't know where they got the squared from.

The third one again uses a perfect cube.

Number four I though would just be the well known F=MA I don't know where the length or T squared come in

and number five makes sense...

Can anyone clear this up, i'm baffled... thanks

BTW the link to the page i'm refering to is: http://www.physics.uoguelph.ca/tutorials/dimanaly/dimanaly_ans1a.html

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Dimensions help

**Physics Forums | Science Articles, Homework Help, Discussion**