Measurement: Tools and Units

Distance• Base Unit: meter (m)–Also Common: km, cm, mm

• Length is a measure of distance.• Tool: Meter Stick, Ruler–1 meter = 100 cm = 1000 mm

To Find the Length of an object:

• Determine what units to use (based on size).• Line up one end of the object with “zero” (be

careful here!).• Read the mark where the other end of the

object is. Estimate between marks.

cm 1 2 43 5

Measurement PracticeMeasure and record the following distances:1. Length of one expo marker = _____ cm2. Diameter of one expo marker = _____ mm3. Length of one table (long edge) = _____ m4. Width of one table (short edge) = _____ m5. Thickness of table (just the top) = _____ cm6. Length of one floor tile = _____ cm7. Length of room (door to door) = _____ m8. Width of room (wall to wall) = _____ m

Mass• Unit: gram (g)–Also Common: kg, mg

• Mass is the measure of how much matter is in an object (amount of “stuff”).

• Tool: Triple-Beam Balance

Mass• NOTE!!!– Mass is NOT the same thing as weight!• Mass is a measure of how much matter is in an object.• Weight is a force that can be calculated based on an

object’s mass.

– On the moon…• A person will have the same mass as on Earth• A person will weigh less than on Earth

Using a Triple-Beam Balance:1. Zero the Balance–Make sure the Pan is clean. Move the

sliders to zero and make sure the pointer lines up with the zero line.

2. Place the Object on the Pan3. Move the Sliders until the Pointer lines up

with the Zero Line– Start with 100’s slider, then 10’s, then 1’s.

4. Add the Sliders together

The “Cup” Method• If you are trying to find the mass of an object

that will not stay on the pan (marble):1. Place an empty cup on the pan and find its

mass.2. Place the object in the cup and find the

new mass.3. Subtract the mass of the cup (1) from the

mass of the object and cup together (2). You are left with the mass of the object.

Using a Digital Scale1. Make sure the scale is plugged in and turned on.2. Check to make sure the units are “g” for grams.– If not, push the “mode” button until the units are “g”.

3. Zero the balance by pressing “zero”.– Wait until the balance reads “0.0 g”.

4. Place your object on the pan.5. Record the mass on the display.

Note: For cup method, place the empty cup on the pan, THEN zero the balance.

Mass Measurement PracticeMeasure and record the following masses with both the triple-beam balance and the digital scale:1. Mass of one expo marker2. Mass of one wooden ruler3. Mass of one marble4. Mass of one tennis ball5. Mass of one plastic ball6. Mass of one metal cube7. Mass of empty grad. cylinder8. Mass of 50 mL of water

Triple Beam Balance (g) Digital Scale (g)

Volume• Base Unit: Liter (L)–Also Common: mL, cm3, cc

• Volume is a measure of how much space something takes up.–Tools: Graduated Cylinder or Ruler•Meniscus: the curve that a liquid

makes inside the graduated cylinder•Read the bottom of the curve!

• Volume can also be calculated using a mathematical formula (for regular shapes)

Volume by Formula•Used for finding the volume of

regularly shaped objects1.Rectangular Prism• V = length x width x height

2.Sphere• V = 4/3 x pi x radius3

3.Cylinder• V = pi x radius 2 x height

Volume by Displacement• Used for finding the volume of

irregularly shaped objects (object must sink in water)

1. Record the beginning water level.2. Carefully slide the object into the

graduated cylinder.3. Record the new water level.4. The change in water level is

equal to the volume of the object.

Volume Measurement PracticeMeasure and get Mr. Hanna’s initial for:1. 60 mL of water 2. 44 mL of water

Use a formula to measure the volume of:3. Wooden Block = _____ cm3

4. Ping Pong Ball = _____ cc5. Big Metal Cube = _____ cm3

6. Plastic Cylinder = _____ cc

Use displacement to measure the volume of:7. Metal Block = _____ cm3

8. Marble = _____ cc9. Small Metal Cube = _____ cm3

10. Rock = _____ cc

Temperature• Unit: Degrees Celsius(⁰C)–Also Common: Kelvin (K)

• Temperature is a measure of the speed of the particles in a substance

• Tool: Thermometer–Usually, the thermometer is filled with red

alcohol that will expand or contract depending on the kinetic energy of the molecules.

Time• Unit: Seconds (s)– Also Common: Minutes (min), Hours (hr)

• Tool: Stop Watch1. Press blue button to turn on.2. Press yellow button once to start timing.3. Press yellow button once to stop timing.4. Press blue button to re-set time to zero.

Density• Unit: grams per cubic centimeter (g/cm3)

or grams per milliliter (g/mL)• Density is a value that represents how

tightly packed the particles are in a substance

• Calculated, not measured! d = m/v

Density equals mass divided by volume

d

m

v