Name: ______Date:______Period: ______

Lab: Measurement Review

Objectives:

 To make precise measurements using the metric system (SI). Accuracy is important too. To distinguish between accuracy and precision.  To convert the original measurements to lower and higher values by moving the decimal point the correct number of places in the appropriate direction.  To re-familiarize oneself with the tools used in laboratory settings.

Materials:  metric ruler  Test containers (test tube, bottles, cup,  electronic balance etc.)  graduated cylinder (100ml)  marble, rock  Celsius thermometer  caliper  coin, artificial blood, tooth  water samples at different temps  3 different sized bullet casings  pencil

Procedures:

Part 1. Use the meter stick to measure the lab table.

1. How many dimensions do the units for mass and length have? How many dimensions do the units for area, speed, and density have? How many dimensions does volume have? Please know that fundamental units have only one dimension, while derived units have two or more.

2. What is the smallest increment on your measuring tool?

Measurement measure convert convert convert Length of the Desk top ______cm ______mm ______m ______Km

Width of the Desk top ______cm ______mm ______m ______Km

Height of the desk from the floor ______cm ______mm ______m ______Km

calculate calculate calculate calculate Area of the Desk top ______cm2 ______mm2 ______m2 ______Km2 (l x w) Volume of the space beneath the Desk top ______cm3 ______mm3 ______m3 ______Km3 (l x w x h) Part 2. Use the analytical balance or scale to mass the penny, blood drop and tooth. Before you perform the massing, predict the value you might expect. How good are your estimates?

1. Define the verb, “to tare” before going moving to the next step.

2. Why should you never let any substance (metal or wet) to come in contact with the balance pan? What should you use to protect the pan?

3. What is the smallest increment on your measuring tool?

Prediction/ Measurement Actual Mass Estimate Mass of the penny ______g ______g

Mass of one ______g ______g blood drop

Mass of the tooth ______g ______g

Part 3. Use a 100mL graduated cylinder to measure the volume of the test tube, cup and bottle. Think about how best to accomplish this.

1. Is it more accurate to use a beaker or a graduated cylinder for determining volumes? Explain.

2. Which graduated cylinders are more precise, small 10mL ones, or large 100mL ones? Why?

3. What is the smallest increment on your measuring tool/device?

Measurement measure Volume (capacity) of the test tube ______mL

Volume (capacity) of the cup ______mL

Volume (capacity) of the bottle ______mL

Part 4. Use the 100mL graduated cylinder to measure the solid volume of the marble and rock. Use the water displacement method. Put water into the cylinder and note the volume. carefully, place the object under the surface of the water and record the change in the volume of the water. The volume of water will reflect the volume of the object.

1. What is the smallest increment on your measuring tool?

2. Provide an example where you might use the water displacement method when working on a forensics case.

Measurement measure Volume of the ______mL marble Volume of rock ______mL

Part 5. Use the Celsius thermometer to measure the temperature of the water in the refrigerator, on the counter and on the hot plate. Record the direct measurement and then convert measurements to Fahrenheit. The conversion formula is (1.8 X Celsius reading) + 32 = Fahrenheit reading

1. What is the smallest increment on your measuring tool?

Measurement measure convert Temperature of the ______oC ______oF Part room temperature water 6. Use the caliper to measure the Temperature of the width and length of three different ______oC ______oF size refrigerator water bullet casings. Calculate the Temperature of the volume of each bullet casing. In ______oC ______oF the hot plate water space below, create a data table to show your data. Make sure to include UNITS and a scale drawing of each.

Accurate or Precise? Both or Neither? Label each diagram from the following choices:

a) Precise, but not accurate b) Accurate, but not precise c) Neither accurate nor precise d) Both accurate and precise

______

1. Provide 3 reasons why using standard units of measure is important for creating and maintaining a thriving civilization?

2. Suggest why the metric system might be a better system to use when conducting forensic investigations.

3. Why, then, do forensic scientists sometimes us British Imperial Units instead of metric units?

4. Convert:

______seconds to 17 nanoseconds ______microliters to 5 milliliters

5. Create and solve your own metric conversion problem.