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

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# Homework Help: Dimensions help

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