IB Physics Measurement and uncertainties: Significant Figures

The video tutorial covers the concept of significant figures in physics, explaining their importance in measurements and calculations. It draws parallels between significant figures and TV episode lengths, illustrating how insignificant digits are often rounded. The tutorial outlines five key rules for counting significant figures and provides examples to clarify these rules. It also discusses the process of rounding numbers to a specific number of significant figures and highlights the importance of accuracy in measurements. The video concludes with a summary of the key points discussed.

Why do we use significant figures in scientific measurements?

• To make numbers look more complex

• To ensure precision and accuracy in reporting

• To confuse the reader

• To avoid using decimals

What is the first rule for counting significant figures?

• Only the last digit is significant

• The first non-zero digit is the first significant figure

• All zeros are significant

• All digits are significant

In the number 0.2114, how many significant figures are there?

• Five

• Two

• Three

• Four

When rounding 0.073056 to three significant figures, what is the result?

• 0.0731

• 0.073

• 0.07306

• 0.07305

What should you do if the digit immediately right of the last significant figure is 5 or more?

• Remove the digit

• Round down

• Leave it unchanged

• Round up

Why might the accuracy of raw data not depend on the number of significant figures?

• Because significant figures are arbitrary

• Because accuracy depends on the measuring device's resolution

• Because more significant figures always mean more accuracy

• Because significant figures are only for decoration

How should you round your answers in typical scientific calculations?

• To one significant figure

• To two significant figures

• To three significant figures

• To four significant figures

What is the implied uncertainty when a number is displayed without it?

• It is always ±1

• There is no uncertainty

• It is attached to the last significant digit

• It is always ±0.1

What is the significance of the last digit in a number when rounding?

• It may be affected by rounding

• It is always accurate

• It is always zero

• It is never significant

How does the resolution of a measuring device affect significant figures?

• It increases the number of significant figures

• It determines how many significant figures can be recorded

• It doesn't affect them

• It reduces the number of significant figures