Unit 0.5 Review: Measurement and Dimensional Analysis

Accuracy is defined as:

• The closeness of a measured value to a standard or known value.

• The ability to repeat measurements with the same result.

• The difference between the highest and lowest values in a data set.

• The process of collecting data over time.

Precision is defined as:

• The degree to which repeated measurements under unchanged conditions show the same results.

• The closeness of a measurement to the true value.

• The process of measuring something.

• The ability to measure very small quantities.

A measurement that is accurate but not precise is:

• A dart hits the bullseye once, but other darts are scattered far from the center.

• A dartboard where all darts are clustered together but far from the bullseye.

• A thermometer that always reads 2 degrees higher than the actual temperature.

• A scale that gives the same reading every time, but the reading is incorrect.

A measurement that is precise but not accurate is:

• A dartboard where all darts land close together but far from the bullseye.

• A dartboard where all darts land on the bullseye.

• A dartboard where darts are scattered all over the board.

• A dartboard where darts are both close together and on the bullseye.

Precision refers to how close a measurement is to the actual value.

• T

• F

You can have precision without accuracy.

• T

• F

Significant figures include all certain digits and one uncertain digit.

• True

• False

True or False: 0.00230 has 5 significant figures.

• True

• False

Identify the number of significant figures in each value: 0.00970 = ______ sig figs

• 3

• 2

• 4

• 1

Identify the number of significant figures in each value: 101.00 = ______ sig figs

• 2

• 3

• 4

• 5