## 1.2.2 Derived Quantities

Derived Quantities

A derived quantity is a Physics quantity that is not a base quantity. It is the quantities which derived from the base quantities through multiplying and/or dividing them.
Example

(Speed is derived from dividing distance by time.)

Derived Unit
The derived unit is a combination of base units through multiplying and/or dividing them.
Example 1
Find the derived unit of density.
Unit Conversion
Area and Volume
Example 2
Convert the unit of length, area and volume below to the units given.
a) 7.2 m = ____________cm
b) 0.32 m2 = ____________cm2c) 0.0012 m3 = ____________cm3d) 5.6 cm = ____________m
e) 350 cm2 = ____________m2f) 45000 cm3 = ____________m3Answer
a) 7.2 m = 7.2 x 102 cm
b) 0.32 m2 = 0.32 x 104 cm2 = 3.2 x 103 cm2
c) 0.0012 m3 = 0.0012 x 106 cm3 = 1.2 x 103 cm3
d) 5.6 cm = 5.6 x 10-2 m
e) 350 cm2 = 350 x 10-4 m2 = 3.5 x 10-2 m2
f) 45000 cm3 = 45000 x 10-6 m3 = 4.5 x 10-2 m3

Speed
Example 3
Complete the following unit conversion
a) 12 kmh
-1 = __________ ms-1
b) 12 ms
-1 = __________ kmh-1

a) $\begin{array}{l} 12km{h^{ - 1}}\\ = \frac{{12km}}{{1h}}\\ = \frac{{12000m}}{{60 \times 60s}}\\ = 3.33m{s^{ - 1}} \end{array}$

b)
$\begin{array}{l} 12m{s^{ - 1}}\\ = \frac{{12m}}{{1s}}\\ = \frac{{\frac{{12}}{{1000}}km}}{{\frac{1}{{3600}}h}}\\ = 43.2km{h^{ - 1}} \end{array}$

1. Anonymous // March 10, 2009 at 8:54 AM

Now i know how to answer questions like this ! Thank you so much!

2. Anonymous // May 14, 2009 at 1:13 AM

thankyou u so much!
i am facing my physic test on tomorrow...lucky i view your website...it helps me a lot!

3. Memes // May 14, 2009 at 9:01 AM

lolz..im havin my test on friday

this site is vry good ^^

4. ae_tone // May 15, 2009 at 1:58 AM

hey i just knew about dis website.
its very good.
i'm havin my exam next week...
it helps me a lot
thank you
thanx
tq
???!!!

5. Safinah Rashid // June 20, 2009 at 9:05 PM

hey, found your blog last week.

im very very weak in physic and your web is helping me to get better marks for physic in SPM.

thanks a lot :D

6. mary // August 29, 2009 at 6:31 AM

thanks a lot 4 all the notes....the notes are really helpful...=)

7. Unknown // December 1, 2009 at 7:48 AM

Hey! after PMR exam is over, I get prepare and study Science Form 4... But why the chapter 1 is easy as shit!?!? OMG...

8. Unknown // February 10, 2010 at 9:08 PM

thank for it, now i can understand it so much

9. Unknown // February 10, 2010 at 9:10 PM
This comment has been removed by the author.
10. MiZ BLuE_HeArT // March 1, 2010 at 2:51 AM

i am sitting 4 my physics test tomorrow~ luckily i found this site!! it helps me a lot!! thanx~

11. qaseh sakura // April 29, 2011 at 4:18 AM

=.=" physics!!! ....

12. Hui // May 19, 2011 at 8:27 PM

its good

13. Hui // May 19, 2011 at 8:28 PM

it's a good note

14. umair awan // January 30, 2012 at 7:06 AM

hhrteiwgvdfnfjjf dydf fygf guydf ygrdyewgfd dygwed yegwyfdug dyewgdyu

15. Unknown // February 12, 2013 at 5:42 AM

thank you very nuch for this working.hope will have same blog for all subjects.thank you :)

16. Unknown // September 17, 2013 at 8:46 AM

sorry but my physics and maths are very poor. i dont understand and do not know how to do the questions. could you show more detailed working methods?

17. glamour with ada marcella OFFCIAL // November 11, 2013 at 7:59 AM

Thanks for the notes. I'm not a pure science student but I'm interested in the subject of physics because I want to be an aircraft engineer.

18. Unknown // January 12, 2015 at 5:16 AM

pheww....today is my first day being science student n wow..physics really kill me...haha...btw thnks for this note..now i could understand a little bit ..i cant understand all of it cuz my teacher gave me a question paper but he didnt teach us first..

19. Unknown // January 14, 2015 at 5:09 AM

InHad my second physics lesson today!Feeling new and don't need to use BM for physics!woohoo!!
Thanks for the note,keep it up!:)

20. Unknown // January 14, 2015 at 5:11 AM

InHad my second physics lesson today!Feeling new and don't need to use BM for physics!woohoo!!
Thanks for the note,keep it up!:)

21. Unknown // March 16, 2015 at 6:18 AM
This comment has been removed by the author.
22. Unknown // January 12, 2016 at 5:14 AM

itz really hard to learn physics in bm...why they never think about our future studies???????shit!!!

23. Unknown // November 28, 2016 at 9:39 PM

Hello:D I wanna ask whether if I can just write the full value of the answer at conversion questions part... Like 0.00024