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. cm12435

Measurement Practice Measure and record the following distances: 1.Length of one expo marker = _____ cm 2.Diameter of one expo marker = _____ mm 3.Length of one table (long edge) = _____ m 4.Width of one table (short edge) = _____ m 5.Thickness of table (just the top) = _____ cm 6.Length of one floor tile = _____ cm 7.Length of room (door to door) = _____ m 8.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 Pan 3.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 Scale 1.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 Practice Measure and record the following masses with both the triple-beam balance and the digital scale: 1.Mass of one expo marker 2.Mass of one wooden ruler 3.Mass of one marble 4.Mass of one tennis ball 5.Mass of one plastic ball 6.Mass of one metal cube 7.Mass of empty grad. cylinder 8.Mass of 50 mL of water Triple Beam Balance (g) Digital Scale (g)

Volume Base Unit: Liter (L) – Also Common: mL, cm 3, 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 objects 1.Rectangular Prism V = length x width x height 2.Sphere V = 4/3 x pi x radius 3 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 Practice Measure and get Mr. Hanna’s initial for: 1.60 mL of water mL of water Use a formula to measure the volume of: 3.Wooden Block = _____ cm 3 4.Ping Pong Ball = _____ cc 5.Big Metal Cube = _____ cm 3 6.Plastic Cylinder = _____ cc Use displacement to measure the volume of: 7.Metal Block = _____ cm 3 8.Marble = _____ cc 9.Small Metal Cube = _____ cm 3 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 Watch 1.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/cm 3 ) 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