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## Ruchi. 3 years ago how to find dimension of any physical quantity?

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1. Ruchi.

@mukushla @mathslover @shruti @SUROJ @ashna @Preetha @PaxPolaris

2. SUROJ

I guess there are 3 dimension lenght, bredth and height

3. SUROJ

and if you consider forth time dimension

4. ashna

In the SI system, the dimension of all physical quantities is a combination of the 7 fundamental quantities such as ..

5. ashna

Name Unit Symbol Distance Meter L Mass Kilogram M Time Second T Current Ampere I Light Candela J Heat Kelvin K Concentration Mole N

6. mathslover

Ok so there are two types of units: 1) Basic (given above by ashna) 2) Derived for example: speed = distance /time unit of distance = metre and unit of time = second hence unit of speed = m/s

7. mathslover

reprsentation : [SPEED] = \(\large{[LT^{-1}]}\)

8. mathslover

is this what u wanted @Ruchi. ?

9. ashna

@Ruchi. candela sybol is cd sorry !

10. mathslover

right J is the symbol of Joule ( unit of energy )

11. ashna

Any physical quantity Q can then be dimensionally expressed as [Q] = L^1 M^2 T^3

12. ashna

THE ONE WHICH SEEMS TO BE POWERS IN MATH IS CALLED DIMENSIONS IN PHYSICS

13. ashna

P.S though not every where

14. ashna

do you have any books to refer to ?

15. Ruchi.

@mathslover i don't know how to find dimension of any physical quantity.

16. mathslover

Of any physical quantity :? you mean like find the dimensions of velocity , speed etc.?

17. ashna

Area = length * length = L^2 UNDERSTOOD ? @Ruchi.

18. Ruchi.

any i mean plz tell me that hw can we find dimension of any quantity.

19. Ruchi.

okay

20. ashna

Volume = Length * area = Length * Length * Length = L^3

21. ashna

understood that ?

22. Ruchi.

yes

23. ashna

do you intent someone else to explain , or am i to continue ?

24. Ruchi.

plz continue

25. ashna

okay

26. ashna

Angle = Arc / Radius = no dimensions

27. ashna

you know why ?

28. Ruchi.

why?

29. ashna

arc = L radius = L so both gets cancelled

30. ashna

understood ?

31. Ruchi.

ok

32. ashna

Density = Mass / Volume = M / L^3 = M^1 L^-3

33. ashna

|dw:1344583056345:dw|

34. ashna

OKAY ?

35. Ruchi.

ok

36. ashna

velocity = displacemnt / time = LT^-1

37. ashna

SINCE DISPLACEMENT = DISTANCE = L

38. Ruchi.

how? i hav nt under stood it

39. ashna

okay , displacement = distance = L (length) divided by time (t)

40. ashna

|dw:1344583266349:dw|

41. ashna

now okay ?

42. ashna

you are free to say if you didn't understand it still :)

43. Ruchi.

can i ask u 1 thing

44. ashna

sure :)

45. Ruchi.

okay why u have taken distance=L

46. ashna

distance is nothing but length .

47. ashna

distance travelled , is the length travelled understood ?

48. Ruchi.

yes

49. ashna

where displacement is just the other word for distance , displacement is the shortest dist travelled and distance is the longest possible distance = L (length)

50. ashna

can i proceed ?

51. Ruchi.

okay above u hav posted a table i table i hav find out that table i many bookbt i don't know how and where i hav to use that table.:"(

52. ashna

Name Unit Symbol Distance Meter L Mass Kilogram M Time Second T Current Ampere I Light Candela cd Heat Kelvin K Concentration Mole mol

53. ashna

this is nothing , i'll explain , dont worry yourself now :)

54. Ruchi.

okay

55. ashna

now i said distance = L , that is the first one , okay ? and its unit is meter .

56. ashna

anything you want to know ?

57. ashna

@Ruchi. you there ?

58. Joseph91

Dimension of a body is determined by the co-ordinate axis attach to it. There are 1D, 2D, 3D and 4D(It includes Time).The existence of 4D is beyond our imagination.

59. Ruchi.

@ashna

60. Ruchi.

@ashna hav studied chapter work energy &power

61. ashna

hey ruchi .. tell me a time when you can stay on in open study for like hours .. not mins , i'll help you with dimensions then ;)

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