Equation for uncertainty in :
Equation for uncertainty in m2:
Gradient of the best fit line:
mBF =
Gradient of the maximum line:
Gradient of the minimum line:
Average of m2 of the metre rule:
Average uncertainty of m2 of the metre rule:
Average m2 of the metre rule with uncertainty:
0.101 8.26210-3 (kg)
The actual mass of the metre rule is: 0.098 0.001 (kg)
Conclusion and Evaluation:
The actual mass is slightly lighter than the calculated value.
0.1010.008 (kg) >0.0980.001 (kg)
This different cause by some sources of error that occurs during the experiment.
As usually the force apply on the 2 end of the rule by the wind blow is not balanced. Especially in the physics labs there are air-conditioners. So this factor can cause the difference in recording the pivot point.
Furthermore, when we hang the masses on the other end of the ruler and we measure the distance d1 and d2, the rule is not exactly balance which mean it’s not totally parallel to the surface of the table so the pivot point also can be recorded wrongly. Therefore, the mass and the distance d2 also be slightly wrong from the actual value.
The bar of a clamp also cause a problem. The contact surface of it is not stable. And when record the pivot point we have to take the mid point, or the centre of the round surface of the bar for a better results.
Beside all the other errors, there’re always an uncertainty error existed.
Suggest ways in which the accuracy of the measurement taken could be improved.
Switch of the air-conditioners in the physics labs. Close all the windows.
Try to take the pivot point when the rule is balance which means almost parallel to the table surface so we can have the best record value.
Check the string tie at one end of the rule so we can make sure that the clockwise moment is correct.
