1. What is absolute uncertainty? (+one example)

2. What is relative uncertainty? (+one example)

1. Absolute uncertainty, also known as absolute error, is a measure of the degree of uncertainty or error associated with a particular measurement. It quantifies the difference between the measured value and the true or accepted value. Absolute uncertainty is typically expressed in the same unit as the measurement itself.

Example: Let's say you are measuring the length of a pencil using a ruler with markings in centimeters. If your measurement is 14.2 cm and the true length of the pencil is 15.0 cm, the absolute uncertainty would be the difference between the two values, which is 0.8 cm.

To calculate the absolute uncertainty, you subtract the measured value from the true value. In this case, it would be: Absolute uncertainty = true value - measured value = 15.0 cm - 14.2 cm = 0.8 cm.

2. Relative uncertainty, also known as relative error or percent error, compares the absolute uncertainty of a measurement with the magnitude of the measurement itself. It provides a relative measure of the error, allowing for comparison between measurements of different magnitudes. Relative uncertainty is typically expressed as a percentage or fraction.

Example: Let's continue with the previous example of measuring the length of a pencil. If the absolute uncertainty is calculated to be 0.8 cm and the measured length of the pencil is 14.2 cm, the relative uncertainty can be determined by dividing the absolute uncertainty by the measured value and multiplying by 100 to express it as a percentage.

To calculate the relative uncertainty, you use the formula: Relative uncertainty = (absolute uncertainty / measured value) x 100

In this case, the relative uncertainty would be: Relative uncertainty = (0.8 cm / 14.2 cm) x 100 ≈ 5.63%

So, the relative uncertainty of the measurement of the pencil's length is approximately 5.63%.