Author Topic: ABSOLUTE ERROR IN PHY P5  (Read 780 times)

Offline hira

  • SF Immigrant
  • **
  • Posts: 52
  • Reputation: 10
ABSOLUTE ERROR IN PHY P5
« on: June 08, 2010, 03:15:02 pm »
please help me in finding the absolute error in physics P5

if a length is giving for eg 6 +- 0.4 ...find L^2 and its absolute erro

please help me please

Offline falafail

  • SF Master
  • ******
  • Posts: 1328
  • Reputation: 1486
  • Gender: Female
  • ab3'a 7asheesh
Re: ABSOLUTE ERROR IN PHY P5
« Reply #1 on: June 08, 2010, 04:54:24 pm »
you find the percentage error first then multiply by the value you get for L^2
here the percentage error is 2 X 0.4/6

Offline Gaz

  • SF Citizen
  • ***
  • Posts: 259
  • Reputation: 282
  • Gender: Male
Re: ABSOLUTE ERROR IN PHY P5
« Reply #2 on: June 08, 2010, 05:05:11 pm »
The question you are referring to is MJ07 P5 Q2b. It is done as follows:
- assume a value of 6+- 0.4. 
- square of 6 is 36.
- 6+0.4= 6.4.  square of 6.4= 40.96
- to find the error in the square, 40.96-36= 4.96
- hence the final answer to be recorded in the table is 36+- 5.0

Note that i put 5.0 instead of 4.96. The mark scheme allows a range of 4.6-5.0. You should use the same number of decimal places that the question uses.
In theory, there is no difference between theory and practice. But in practice, there is.

Offline wildrider

  • Newbie
  • *
  • Posts: 37
  • Reputation: 14
Re: ABSOLUTE ERROR IN PHY P5
« Reply #3 on: June 08, 2010, 05:27:16 pm »
please help me in finding the absolute error in physics P5

if a length is giving for eg 6 +- 0.4 ...find L^2 and its absolute erro

please help me please

1st- 0.4/6*100=6.67%
2nd- 6.67*2=13.3%
3rd- 13.3*36/100= 4.8
->    36+-4.8