MediumPhysicsHigh School (11–12)Mechanics › Units and MeasurementNumerical

Five readings of the length of a pencil are 17.6 cm, 17.4 cm, 17.7 cm, 17.5 cm and 17.3 cm.

Try it on paper first. A hint, the key idea and the worked solution are here when you need them.

Five readings of the length of a pencil are $17.6\ \text{cm}$ , $17.4\ \text{cm}$ , $17.7\ \text{cm}$ , $17.5\ \text{cm}$ and $17.3\ \text{cm}$ . Find the mean, the mean absolute error and the percentage error, and write the result.

Need a reminder? The key ideaShow

For readings $a_1, \ldots, a_n$ : the best value is the mean $\bar{a}$ ; each absolute error is $|a_i - \bar{a}|$ ; their mean is the mean absolute error $\Delta\bar{a}$ .

\displaystyle \text{relative error} = \frac{\Delta \bar{a}}{\bar{a}}, \qquad \text{percentage error} = \frac{\Delta \bar{a}}{\bar{a}} \times 100\%

The worked solution

Have you tried it?

Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.

← All Problems

← Say whether each error is systematic or random: a measuring tape that has stretched with use; gusts…A student finds the acceleration due to gravity with a pendulum and gets 9.65 m/s². →

More onMechanics › Units and Measurement

Discussion (0)

Loading…