Aim: How do we measure? DO NOW: TAKE A MIN TO THINK ABOUT - WHAT’S THE DIFFERENCE BETWEEN 15 APPLES AND 15 ORANGES? If I just say 15, would you know, if it is apples or oranges without any other information?

Do Now: What are some units you can think of? (THINK PAIR SHARE) COME UP WITH 5 DIFFERENT UNITS AND THINK FOR WHAT ARE THEY USED. FOR MASSFOR LENGTHFOR TIME FOR AREAFOR VOLUMEOTHER UNITS Aim: Why are units so important? EQ: What is essential to Succeed in physics class?

The seven SI base units  The kilogram (kg) - unit of measurement of mass.  The meter (m) - unit of measurement of length.  The second (s) - unit of measurement of time.  The kelvin (K) - unit of measurement of thermodynamic temperature.  The ampere (A) - unit of measurement of electric current.  The Joule (J) – unit of electrical potential energy  The mole (mol) - unit of measurement of amount of substance  The candela (cd) - unit of measurement of luminous intensity

Consider this: What unit would you use?  To measure the distance between your house and the school in? (m)  To measure the time interval it takes for a cake to bake?  To measure the mass of the grocery bag your mom just asked you to carry?

Some Examples of SI derived units expressed in terms of base units Derived QuantitySI derived unit NameSymbol areasquare metrem2m2 volumecubic metrem3m3 speed, velocitymetre per secondm/s accelerationmetre per second squaredm/s 2 Force1 NewtonKgm/s 2 density, mass densitykilogram per cubic metrekg/m 3 current densityampere per square metreA/m 2 magnetic field strengthampere per metreA/m PowerWattJ/s

Consider this: What unit would you use?  To measure how fast are you driving? (m/s)  To measure how much faster you need to go in order to pass the car next to you?  To measure the force you need to move your furniture?  To measure how big the base of the object above your table is?  How about the size of the full object?

Prefixes for Powers of 10 PrefixSymbolNotation teraT10 12 gigaG10 9 megaM10 6 kilok10 3 decid10 –1 centic10 –2 millim 10 –3 microµ10 –6 nanon 10 –9 picop10 –12

Consider this: What unit would you use?  To measure the size of a microbe? (nm)  To measure the mass of your morning coffee? (g)  To measure how fast the train is traveling on average? (Km/hr)

Try these: What unit would you use?  To measure how tall your finger is?  To measure the width of your finger?  To measure how high the ceiling is?  To measure the distance between your house and the school in?

What is meant by precision?  How precise is the measurement?  Depends on the equipment you use.  The last digit is estimated.

Measurement Activity. (Start of LAB)  Measure objects around you, including the ones the teacher tells you to, and be ready to share your results.

Solve:  15m + 15 m =  2cm + 2m =  500g + 1.3kg =  5s hr =

Solve:  2.00cm x 0.13m =  5.40m x km =