1. Measurements
Earth Science

2. International System
From the French Le Systeme International d’Unites….SI system.
Used by all scientists around the world to ensure all measurements are consistent.
Very simple to use! All units are easy to convert by simply moving the decimal (uses the power of 10)

3. International System

4. Length Basic Unit: meter Often measured with a _______ stick
Smaller units: centimeter, millimeter
Centi= one hundredth of a meter
1 meter = _____________ cm
Milli= one thousandth of a meter
1 meter = _____________ mm

5. Length Larger Unit: kilometer Kilo = 1000 meters
1 kilometer equals 0.62 miles
A 10 km road race = 6.2 miles!

6. Length Different lengths require an appropriate unit
What unit would you use to measure the following:
Distance from home to school_____________
Distance around a track_________________
Length of a pencil______________________
Width of a pencil______________________

7. Mass Measure of the AMOUNT OF MATTER in an object. Basic unit: Gram
Mass depends on the number and kinds of atoms – Measured using a balance.
Kg-used for large items, such as a car/person
G-used for smaller objects

8. Volume The amount of space an object takes up
Basic Unit: cm3 or mL (milliliter)
1 cm3 = 1 mL….they take up the same amount of space.
2 different ways to calculate volume depending on whether or not the specimen is a regularly or irregularly shaped object

9. Volume
Regularly-shaped objects: have smooth solid side, with a definite geometric shape
Volume=Length x Width x Height (LxWxH)
2cm x 2cm x 2cm = 8cm3

10. Volume
Irregularly-shaped objects have no defined shape, such as a rock.
Uses the water displacement method
Record Initial volume
2. Insert object
3. Record Final volume
4. Subtract: V = F – I
9 mL – 2 mL = 7 mL
…..or 7 cm3!
-always measure at the bottom
of the meniscus!

11. Density
Defined as mass per unit of volume….or how much mass is in a given space.
How tightly “packed” the atoms are.
The higher the density, the tighter the molecules are packed together, more mass in a given space.
Calculated: Density = Mass / Volume
Units: g/cm3 or g/mL

12. Density Suppose a substance has a mass of 10 g and a volume of 10 ml
D = m/v
D = __________ / ____________
D = 1 g/ml…this is pure water, which always has a density of 1 g/ml

13. Density
Density is a physical property! It always stays the same, no matter the size of the object.
If you break an object in half, each half will have less mass AND less volume than the object as a whole
Therefore, the density will still calculate to be the same.

14. Density
Example: A rock with a mass of 16 g and a volume of 8 ml has a density of 2 g/ml
D= m/v D = 16g/8ml = 2 g/ml
If the rock is broken in half, each piece would have half the mass and volume as the original

15. Density Rock A= 8g & 4 ml Rock B = 8g & 4 ml Although the rock is now
smaller, the density
stays the same!
Density is a physical
Property
Can be used to identify
an object
Rock A= 8g & 4 ml Rock B = 8g & 4 ml

16. Density
Objects of different densities will separate, with the highest density on the bottom, and the lowest density on the top.
EX: layers of the earth. The core has the highest density, its in the center. The crust has the lowest density, its on the surface. As you go up from the core, density decreases with each layer.

17. Density Density of water =________________
If an object is greater than 1 g/ml, then it will sink
If an object is less than 1 g/ml, then it will float.
Is ice greater or less than 1 g/ml?

18. Density
Indicate whether the following item would sink or float in water:
Wood D=0.67g/ml _________
Golf Ball D=4.2g/ml _________
Ping Pong D=.36g/ml _________

19. Density
If you know any two variables (m, v, or d), you can solve for the other one.

20. Weight
Measures the force of attraction between two objects due to gravity
On earth, your weight is a measurement of the earth’s gravity pulling down on your mass.
Unit: Newton (pounds in this country)
Measured with a scale

21. Weight The force of gravity (weight) depends on mass and distance
The more massive an object, the more it will weigh.
The closer two objects are, the more they will weigh.
You actually weigh less on a mountain than at sea level! Why?
You’re farther from the center of the earth!

22. Weight
The moon is much smaller than the earth, & therefore is made of much less mass (matter). You would weigh 1/6th of what you weigh on earth!
Since Jupiter is much larger than Earth, you would weigh a great deal more! Too heavy to move even.

23. Review-fill in the following formulas
Mass =
Volume =
Density =

24. Percent Error
Accepted Value – Measured Value Accepted Value
X 100

25. Review Terms to know: Length Mass Volume Density Weight
Water displacement method