# Quiz How many significant figures are there in the number 45.07 cm? (5 points) Express the operations correctly (5 points each) a. 34.56 cm + 3 cm = b.

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Quiz How many significant figures are there in the number 45.07 cm? (5 points) Express the operations correctly (5 points each) a. 34.56 cm + 3 cm = b. 34.56 cm X 3 cm =

Dimensions, Units, Metric System, Dimensional Analysis Homework: Skim Ch. 1. Complete the handout

I. Dimensions. Physics is a science founded on observation and measurement. Measurements are used to convey information gained about the world around us. ____________ are measurable physical properties.

I. Dimensions. Physics is a science founded on observation and measurement. Measurements are used to convey information gained about the world around us. Dimensions are measurable physical properties.

Here are a few examples: Length, Time, Mass, Charge, Temperature, Rate, Speed

Dimensions are divided into two types, ____________ and ____________. Fundamental dimensions are just as their name indicates, these are the basic building blocks used to set the framework of measurements.

Dimensions are divided into two types, fundamental and derived. Fundamental dimensions are just as their name indicates, these are the basic building blocks used to set the framework of measurements.

We will use only three basic building blocks for the entire first semester: ______, ____, and ____. Each of these is defined in section one of the text.

We will use only three basic building blocks for the entire first semester: length, mass, and time. Each of these is defined in section one of the text.

Derived dimensions are made of combinations of fundamental dimensions. Here are some examples: area = (length) 2,volume = (length) 3

II. Units.Units are ____________ values given to the dimensions above. Standardization is necessary; else measurements can easily become meaningless. These are three main systems used today: _____, _____, and the _______ system

II. Units.Units are standardized values given to the dimensions above. Standardization is necessary; else measurements can easily become meaningless. These are three main systems used today: _____, _____, and the _______ system

II. Units.Units are standardized values given to the dimensions above. Standardization is necessary; else measurements can easily become meaningless. These are three main systems used today: m k s, c g s, and the british system

The first two are part of the metric system, a system built off of powers of 10. SI, or mks, is the current standard.

The mks stands for _____, ________, and ______, representing length, mass, and time

The mks stands for meter, kilogram, and second, representing length, mass, and time

The other, older system is cgs, which stands for __________, ____, and ______.

The other, older system is cgs, which stands for centimeter, gram, and second.

Each of the units has the same set of multipliers, allowing each unit to be increased or decreased in amount by factors of ten. These are the multipliers that you must memorize:

namesymbolmultipliernamesymbolmultiplier femtof10 -15 decid10 -1 picop10 -12 dekada10 1 nanon10 -9 hectoh10 2 microμ10 -6 kilok10 3 millim10 -3 megaM10 6 centic10 -2 gigaG10 9

The main benefit of the metric system is that it is ______, ___________, and _____________________. Here are some examples of the usage of the prefixes:

The main benefit of the metric system is that it is simple, easy to use, and based on powers of 10. Here are some examples of the usage of the prefixes:

kilogram = 1000 grams millimeter = 0.001 meter decibel = 0.1 bel

III. Dimensional Analysis: Dimensional analysis refers to the process of converting one set of units into another. Here are a few examples:

1. 125 mL = ? L

or

2. 155 km = ? m

or

3. 8.5 mm = ? dm

or

4. 0.0278 kg = ? mg

or

5. 0.000 008 8 mm = ? dam

The conversions between metric and British units are not as easy. The conversions are actually definitions, and are considered exact. Highlight these for memorizing! 1 foot = 12 inches, 1 yard = 3 feet = 36 inches, 1 mile = 5280 feet 1 inch = 2.54 cm, 1 liter = 1000 cc = 1000 cm 3, 1 gallon = 4 quarts 1 day = 24 hours, 1 hour = 60 minutes = 3600 seconds 1 micron = 1 micrometer = 1 μm, The density of water = 1.000 g/cm 3.

Example #1: How many inches are in 0.00435 mile?

Don’t forget proper significant figures!

Example #2: How many firkins can be held in one hogshead ?

Since all conversions are exact, this is considered an exact computation.

Example #3: How many meters are in one mile ?

Since all conversions are exact, this is also considered an exact computation.

Example #4: How many liters of water are contained in Mr. J’s 55- gallon piranha tank ?

Again watch for proper use of significant figures.

Example #5: How many square yards of carpet are needed to cover an apartment that measures 955 square feet ?

or

Example #5: How many square yards of carpet are needed to cover an apartment that measures 955 square feet ? Be sure to raise all conversion factors to the correct power! or

Example #6: A car is traveling at 65.0 mph. Convert this speed to meters per second ?

Example #7: A Hummer H2 averages 10.3 mpg. How many liters of fuel will this vehicle consume per 100 kilometers traveled ?

Use the conversions to determine how many liters are needed to drive 100 km.

Example #7: A Hummer H2 averages 10.3 mpg. How many liters of fuel will this vehicle consume per 100 kilometers traveled ? Use the conversions to determine how many liters are needed to drive 100 km.

Example #8: Mr. Mosig has an aquarium that measures 18.0 inches wide, 2.00 feet tall, and 2.00 yards long. What is the weight of water held in this tank ?

Example #9: Steel has a density of 7.87 g/cm 3. What is the density in lb/ft 3 ?

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