Paper 3

Question 1

How do you get an estimate for the percentage uncertainty in your value of x?

Question 2

Answer 1

• Find the smallest possible measurement in your equipment (ruler would be 1mm)
• Thus your absolute uncertainty is x +/- 2mm
• Percentage uncertainty = (Absolute uncertainty/Measured Value) x 100

Question 2

What is your justifying statement for number of sig figs used in your second value of the constant?

If you used 3 sig figs

Answer 2

• Every calculated value must be given to the number of sig figs as (or one more than) the least sig figs in the corresponding vales measured in the experiment
• Hence I used 3

Question 3

How do you show whether or not the results support the suggested relationship

Answer 3

• Find the percentage difference in calculated values
• Set criterion of 10%
• State that the results do/do not support the relationship as the % difference between values is less/larger than 10%

Question 4

What are the statements you can always use for the two 4 mark sections at the end?

Answer 4

• 2 readings are not enough to draw a valid conclusion
• Take more readings and plot a graph