The Science of Physics Chapter One

What is Φΰσις” ? Physics: from the greek word “Φΰσις” ( Physis: meaning nature The study of all the natural sciences Motion through spacetime Matter Gravity Light Energy Force Physics is the analysis of nature

What is Φΰσις” ? Thales: Democritus: Ptolemy: Archimedes: Pythagoras: first to question what makes matter Democritus: Origin of atoms Ptolemy: Nature of the stars Archimedes: Engineering and buoyancy Pythagoras: Quantitative answers

What is Physics? Physics is the study of the physical world. It explains how things work and why they do what they do.

Scientists use models to simplify things For example: Imagine studying the motion of a sailboat from one point to another.

Models Ignore things that don’t matter (color, shape, waves, wind, sounds, etc.)

Models Ignore things that don’t matter (color, shape, waves, wind, sounds, etc.) Treat the boat as a point with no shape, the water as a smooth surface, and wind blowing in only one direction

The Scientific Method Imagine a police investigation of a car accident. You are the detective. How would you figure out what happened?

Step 1: Make observations and collect data Step 2: Form a Hypothesis (also called an educated guess) - I think this is what happened…. Step 3: Do experiments to test your hypothesis Step 4: Revise hypothesis, if necessary, according to experimental data Step 5: Draw a final conclusion: “This is what happened”

The SI System of Measurement (International System) International - used to communicate results to anyone throughout the world. - based on powers of ten Easy Give him 2.54 cm and he’ll take 161 000 cm Give him an inch and he’ll take a mile 91 61 91 (cm) 36 24 36

meter (length) meter (length) kilogram (mass) gram (mass) The 3 Fundamental units in the SI system : Base Units Fundamental Units meter (length) kilogram (mass) second (time) meter (length) gram (mass) second (time)

Cannot be just a number. Must have a unit with the quantity. Measurements Cannot be just a number. Must have a unit with the quantity. Dimension - Description of what kind of quantity is represented by a measurement Three Fundamental or Basic dimensions 1. Length 2. Mass 3. Time

Derived Units: Formed by combining fundamental units with multiplication or division. Examples: m3 m/s kg m/s2 m/s2 (newton)

Merry king henry died belly up drinking chocolate malted milk mega M k Power of 10 SI Prefixes Merry king henry died belly up drinking chocolate malted milk ______ ____ 1 000 000 106 mega M k ______ ____ 1 000 103 kilo ______ ____ 100 102 hecto h ______ ____ 10 101 deka da base unit meter, gram, liter etc ______ ____ 1/10 10-1 0.1 deci d ______ ____ 1/100 10-2 0.01 centi c ______ ____ 1/1000 10-3 0.001 milli m ______ ____ 1/1000 000 10-6 0.000 001 micro m

SI Prefixes ______ ____ 1 000 000 106 mega M k ______ ____ 1 000 103 kilo ______ ____ 100 102 hecto h da ______ ____ 10 101 deka base unit meter, gram, liter etc ______ ____ 1/10 10-1 0.1 deci d ______ ____ 1/100 10-2 0.01 centi c ______ ____ 1/1000 10-3 0.001 milli m ______ ____ 1/1000 000 10-6 0.000 001 micro m

Conversion: chart method ( step method) Move up the chart one step Move decimal to left or Subtract 1 from exponent kilo to mega Count as 3 steps micro to milli

Convert 1,235 g to kg

mega M kilo k hecto h deka da base unit 3 steps 4 steps up 1 step Convert 2,230 hm to Mm ______ ____ 1 000 000 106 mega M ______ ____ 1 000 103 ______ ____ 100 102 kilo k hecto h ______ ____ 10 101 deka da base unit meter, gram, liter etc 3 steps 4 steps up 1 step 4 decimal places left 2,230 hm 0.2230 Mm

base unit deci d centi c milli m micro 3 steps 3 steps Convert 5 000 000 000 mg to g 6 steps up ______ ____ 1/1000 000 10-6 0.000 001 base unit meter, gram, liter etc ______ ____ 1/10 10-1 0.1 deci d ______ ____ 1/100 10-2 0.01 centi c milli m micro 3 steps ______ ____ 1/1000 10-3 0.001 3 steps 5 000 000 000 mg 6 decimal places left 5 000 g

mega M kilo k hecto h deka da base unit ______ ____ 1 000 000 106 Convert 1.5 x 108 m to km ______ ____ 1 000 000 106 mega M ______ ____ 1 000 103 ______ ____ 100 102 kilo k hecto h ______ ____ 10 101 deka da base unit meter, gram, liter etc 3 steps up 1 .5 x 108 m Subtract 3 from exponent 1.5x105 km

Convert 0.0123 Mg to dag

Convert 54,800 L to mL Convert 0.0123 Mg to dag Convert 150000000 m to km Convert 5,000,000 000 mg to g Convert 2,230 hm to Mm Convert 2,230 hm to Mm Convert 2,230 hm to Mm Convert 2,230 hm to Mm