11can error be -ve???
A physical quantity x is being calculated by using the formula x = yz . In a particular set of values , the value of y is measured with an error of +10% , whereas the value of z is measured with an error of -10% . For this particular set of values , the error in the calculation of x will be
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12 Answers
1one more ques .....
the displacement of a particle starting from rest and moving under a constant acceleration is calculated by the formula S = 1/2at2 .if there occurs an error of 30% in the measurement of time interval t , what error will be introduced in the calculation of S ?
1Δ xx = Δ yy + Δ zz
Hence , the error in measuring " x " = 10 % - 10 % = 0 %
1Δ SS = 2 . Δ TT = 60 %
How can the previous answer be 1% ? Please think yourself too .
1my ans is also 0% .may be the ans is incorrect.
ans of second ques is 69%.
1one more ques.....
the length of a pendulum is measured as 20.0cm .the time period of 100 oscillations is measured as 90 s with a stop watch of 1 s resolution . the accuracy in the determination of 'g' is
21Using log- differentiation in error calc. doesnt always gives exact answers
actually (delta) X means verry small.. when we say (delta)X = 30 some error we ourselves do
(i hvnt gone through the previous postes, so may be i'm talking irrelevant )
1Let me solve Q.2 practically...
Let a=5 & t=1
So, s = 1/2 x 5 x 12 =2.5
when there is 30% error in measurement of t then,
s2 = 1/2 x 5 x [1 + (3/10)]2 s2 = 4.225
Now,
s2 - s = 1.725
Again, 1.725/2.5 x 100%= 69%
So, error in calculation of s = 69%