Question

kate is a student in the lab and needs to measure the amount of water in this cylinder. she measures the volume as 44.8 ml. which of the following statements about kates measurement are true? select all that apply. this measurement is an example of an exact number. 45.2 ml is a better measurement for this volume of liquid. in measuring the volume, the value 45 ml contains 2 uncertain digits. this measurement contains uncertainty. 45 ml is a better measurement. the 8 in 44.8 is the uncertain digit.

Explanation:

Step1: Analyze exact - number concept

Exact numbers are obtained by counting or definition, not by measurement. Measurement values like 44.8 mL are not exact. So the statement "This measurement is an example of an exact number" is false.

Step2: Evaluate better - measurement claim

There is no indication that 45.2 mL is a better measurement. The meniscus appears to be at 44.8 mL, so "45.2 mL is a better measurement for this volume of liquid" is false.

Step3: Analyze uncertainty in 45 mL

If we consider 45 mL, the 5 is the uncertain digit, so it has 1 uncertain digit, not 2. So "In measuring the volume, the value 45 mL contains 2 uncertain digits" is false.

Step4: Consider measurement uncertainty

All measurements from a graduated - cylinder have some uncertainty due to the limitations of the measuring device and human error in reading the meniscus. So "This measurement contains uncertainty" is true.

Step5: Evaluate 45 mL as a better measurement

There is no evidence that 45 mL is a better measurement than 44.8 mL as the meniscus is closer to 44.8 mL. So "45 mL is a better measurement" is false.

Step6: Identify the uncertain digit

In a measurement like 44.8 mL, the last digit (8) is the estimated digit and is uncertain. So "The 8 in 44.8 is the uncertain digit" is true.

Answer:

This measurement contains uncertainty.
The 8 in 44.8 is the uncertain digit.