A student measures a boiling water bath with two different thermometers. The digital thermometer records the temperature as 100.2°C and has an uncertainty of 0.1°C. The analog thermometer records the temperature as 99.0°C and has an uncertainty of 0.5°C. What is the percent uncertainty of each thermometer? And what is the percent error given that water boils at 100.0°C?

Explanation:

Measurement made = 100.2 °C

uncertainty = 0.1°C

percent uncertainty = .1 x 100 / 100.2

= .099 %

2 nd thermometer :

Measurement made = 99.0 °C

uncertainty = 0.5°C

percent uncertainty = .5 x 100 / 99

= .505  %

Percent error :

1 st thermometer

Error = 100.2 - 100 = .2 °C

measurement = 100.2

percent error = .2 x 100 / 100.2

= .1996 %

2 nd thermometer

Error = 100.00 - 99 = 1.00 °C

measurement = 99

percent error = 1 x 100 / 99

= 1.01  %