Unit 1 Ch 1 Sec 4 - Working with Measurements

Why is it impossible to make a measurement of the exact true length of an object?

• Because all measurements involve some amount of error or uncertainty

• Because rulers are not accurate

• Because objects change size

• Because measurements are always rounded

What is the definition of significant digits?

• Meaningful digits in a measured quantity

• Digits that are always zero

• Digits that are always one

• Digits that are always two

What what does the third digit tell you in the measurement 2.65 cm?

• The length of the object is exactly 2.65 cm

• The length of the object is in between 2.6 and 2.7

• The length of the object is 3 times larger than actual.

• The length of the object is in between 2 and 3 cm

What is the area of an 8.5-inch by 11.0-inch piece of paper in square inches? (Use significant figures)

What does the term "accuracy" refer to in measurements?

• How close a measured value is to the true value

• How close repeated measurements are to each other

• The smallest interval that can be measured

• The number of significant figures in a measurement

What does "precision" describe in the context of measurements?

• How close a measured value is to the true value

• How close repeated measurements are to each other

• The smallest interval that can be measured

• The number of significant figures in a measurement

What is "resolution" in the context of measurements?

• How close a measured value is to the true value

• How close repeated measurements are to each other

• The smallest interval that can be measured

• The number of significant figures in a measurement

Which of the following best describes a measurement that is accurate but not precise?

• Measurements are close to the true value but not close to each other

• Measurements are close to each other but not close to the true value

• Measurements are neither close to the true value nor close to each other

• Measurements are both close to the true value and close to each other

What is the purpose of estimating the uncertainty or error in measurements?

• To make the results look better.

• To compare the results with other experiments.

• To decide if there is a true difference between two results.

• To avoid repeating the experiment.

In the table in figure 1.11 are the numbers 0.3352 seconds and 0.3349 seconds different?

• Yes, the numbers have different digits.

• No, the numbers are so close to each other that they are considered the same

• Yes, the numbers are far enough apart to be considered different.

• Cannot be determined by the information given.