# 2.5: Thinking about the material

- Page ID
- 19370

## Reflect and research

- Often, physicists will report a measured number with a “standard” uncertainty and indicate that there is a \(68\)% that the true value lies within the range covered by the uncertainty. Where does the number \(68\)% come from?
- Why can the derivative method only be used when the relative uncertainties are small?
- How would you estimate the height of a tall building?

## Experiments to try at home

- Estimate the volume of your room, and how many people could be piled into the room. State your assumptions and how you determined the values.

## Experiments to try in the lab

- Newton’s Universal Theory of gravity predicts that the distance, \(x\), covered by an object that has fallen for a length of time, \(t\), is given by:

\(x=\frac{1}{2}gt^{2}\)

Determine the value of \(g\) (with uncertainty) by performing an experiment that will allow you to determine \(g\) by determining the slope of a line of best fit.