MEASUREMENTS AND CONVERSIONS

METRIC BASE UNITS

•Length – Meter (m)

•Mass – Gram (g)

•Volume – Liter (L)

•Time – Seconds (s)

•Temperature – Kelvin (K)

•Celsius (˚C) Conversion K = ˚C – 273.15

•Current – Amp (A)

PHYSICS OR SI BASE UNITS

•Length – Meter (m)

•Mass – Kilogram (kg)

•Volume – Liter (L)

•Time – Seconds (s)

•Temperature – Kelvin (K)

•Electric Current – Amp (A)

SI DERIVED UNITS

• Velocity: (m/s)

• Acceleration: (m/s²)

•Density: (kg/L)

• Force: mass (kg) x acceleration (m/s²) = Newton (N)

• Energy and Work: Force (N) x Length (m) = Joule (J)

• Power: Work (J) / time (s) = Watt (W)

• Frequency: 1/s = hertz (Hz)

• Electric charge = current (A) x time (s) = coulomb (C)

CONVERSIONS FOR SI UNITS

CONVERSIONS FOR SI UNITS

PRACTICE PROBLEMS

Convert the following to SI base units:

1. 10 g = .01 kg

2. 6 km = 6,000 m

3. 1000 mL = 1 L

4. 7 minutes = 420 s

5. 20 mA = .02 A

6. 3000 mg = .003 g

7. 0.8 cm = .008 m

Piece of Cake

CONVERT STANDARD TO SI UNITS

• 1 mile = 1609.34 m

• 1 yard = .91 m

•1 gallon = 3.79 L

• °F = °C × 9/5 + 32

• 1 lb. = .45 kg (only on Earth)

• 1 lb. = 4.4 N (everywhere)

PRACTICE PROBLEMS

Convert the following to SI base units:

1. 3.1 miles = 4989 m

2. 80 ˚F = 26.7 ˚C

3. 25 mph = 11.2 m/s

4.150 lb. = 68 kg (mass)

5. 150 lb. = 667 N (force)

6. 70 mph = 31.3 m/sGood Job! You did it!

SCIENTIFIC NOTATION

•Scientific notation is the way that scientists easily handle very large numbers or very small numbers. For example, instead of writing 0.0000000056, we write 5.6 x 10-9.

• Speed of light:

• c = 299,792,458 m/s = 3.0 x 108 m/s

•Gravitational constant:

• G = 0.0000000000667 Nm2/kg2 = 6.67 x 10-11 Nm2/kg2

SCIENTIFIC NOTATION

Practice problems:

•123,456,789.00 = 1.23 x 108

•0.00987654321 = 9.88 x10-3

•0.00000789320 = 7.89 x 10-6

•821640732.200 = 8.21 x 108

•0.00000100100 = 1.00 x 10-6

•1309000.02000 = 1.31 x 106

•6780003.99000 = 6.78 x 106

•0.00070900000 = 7.09 x 10-4

Wow!

MEASURING INSTRUMENTS

• Length: Meter stick, Ruler, Calipers, Tape measure

•Mass: Triple beam balance, spring scale, digital scale

• Volume: Graduated Cylinder

• Time: Stop watch

• Force: Spring scale, digital scale

• Temperature: Thermometer, Thermal couple

• Electrical current and charge: Multimeter

NAME THE INSTRUMENT

Calipers Triple Beam Balance

Stopwatch

Graduated Cylinder

Meter stick

NAME THE INSTRUMENT

Spring scale

Thermometer

Thermocouple

Multimeter