Physics 1

• definitions of physics: A tool used to understand the world around us. A science that studies the nature of matter and energy, their interactions, and their effects on living organisms.
• Ask a question you want to understand, figure out how to measure it with numbers, and create a mathematical model based off those numbers.
• difference between science and engeneering is that science is a way of knowing and engineering is a way of doing.
• While science begins with asking questions, engineering begins with defining a problem to solve. The goal of science is to construct explanations for phenomena. The goal of engineering is to solve problems.
• 1. Steps for solving numerical problems in science: 1. Draw picture if helpful 2. Indicate known values 3. Indicate unknown values 4. Indicate equation 5. Plug in values 6. Solve for unknown values 7. write answer with appropriate number of significant digits 8.put a box around the final answer including units.
• meter (m) measures distance. Definiton: 1/10,000,000 of the distance from the equator to the north pole.
• kilogram(kg) measures mass. defined mass of water found in a box that is 10 cm to a side.
• celsius(c) measures temperature. Defined by 1/100 temperature Difference between frozen and boiling water under standard conditions.
• second(s) measure time. Define by tradition - 60 seconds in a minute 60 minutes in an hour 24 hours in a day - that is 1/85 400 of a day.
• Candela(cd) measures brightness light. Light given off by a single candle of a particular typr.
• Ampere(A) measures electric current. The electric flow necessary to create a certain force between wires.
• Mole(mol) measures amount. Number of individual atoms in 1.0000 g of none isotopic hydrogen.
• original 7 fundamental units(SI units): meter, kilogram, second, ampere, celsius, mole, candela.
• 1 in=2.54cm
• 1 kg= 2.2 lb
• 1 m/s=2.24 mph
• 1609m=1 mile
• 1 year=365.25 days
• 16 oz=1 lb
• Linear when X doubles Y doubles
• quadratic when X doubles Y is four times as large
• inverse when X doubles why is half as big
• inverse squared when X doubles Y is 1/4 as big