welcome to physics!!!

Welcome to Physics!!!

The most mathematical of all the sciences

The study of the Universe on all levels

(Particles less than 10-16 to greater than 1024 in the Cosmos)

What Physicists Do?

Physics is

Science Technology

(Ideas) Scientists (Application) Engineers

Why Study Science?

To solve fundamental problems

Understand our future world

Improve quality of life

Physics is Phun!

MechanicsThe Study of Motion and its causes :

Newton's Laws of Motion

Mechanics are understood in basic units of measurements of

length, mass, and time.

Measurements in Metrics (SI = International System of Units)

MeasurementsMKS CGS English

Length Meter (m) Centimeter (cm)

Foot (ft)

Mass Kilogram (kg) Gram (g) slug

Time Second (sec) Second (sec) Second (sec)

1900 Now

Meter = 1/10,000,000 distance

1,650,765.3 wavelengths of

orange- red light from 36 Kr

Second = 1/31,556,925.9747 of the year

1900

9,192,631,770 atomic vibration of 137 Cs

Scientific Notation

2.37 X 107 m

Unit

Power of Ten 0 < y < 10(minimum 2 places behind decimal)

EE EXPor Button on Calculator

The calculator will be your best friend in physics. Never forget it!!!!

Especially on Test day!!!

Rules for Scientific Notation Calculations

Addition and SubtractionMust have same exponents

Must have the same units

Ex.

a) 5 x 107 m + 3 x 107 m = ________

b) 6.2 x 10-3 m – 2.8 x 10-3 m = ________

Multiplication

Add exponents

Treat units as products

Ex.

a) (3 x 106 m)(2 x 103 m) = _________

b) (2 x 10-5 m)(4 x 109 m) = ________

c) (4 x 103 kg)(5 x 1011 kg) = ________

d) (4 x 103 kg)(5 x 1011 m) = ________

Division Subtract exponents

Carry units or cancel out when possible

Ex.

a) 8 x 106 m = ________ m/sec

2 x 103 sec

b) 8 x 106 kg = ________ kg/m

2 x 104 m

c) 9 x 106 m2 = ________ m

4.5 x 107 m

PowersMultiply exponents

Square or cube the number and measurements (units)

Ex.

a) (3 x 102 m)2 = ________

b) (2 x 102 m)3 = ________

Products of variables in Formulas

(Length)(Length) = Area (m2 or cm2)

(Length)(Length)(Length) or (Length)(Width)(Height) = Volume (m3 or cm3)

Length = Distance = d = Speed or Velocity

time time t Units:(km/hr or m/sec)

mass = Density (g/ml or g/cm3)

Volume

Use conversion factors like fractions!

Ex. 55mi = ? km 55mi (1.61km) =

hr hr hr ( 1 mi )

Ex. 55mi = ? m 55mi (1 hr) (1610 m) =

hr sec hr (3600 sec) (1 mi)

Ex. How many cm3 in a qt?

1Qt (.986 L)(1000 ml)(1cm3) =

(1 qt) (1L) (1ml)

Conversion Review

Examples

Ex. If a cylinder has a radius of 156 mm and a length of 8.7cm, How many m3 does it contain?

=> Any variable in an algebraic formula can be replaced by a number and its units.

This makes the quantities in formulas become real – world measurements.

=> Any variable in a formula can be isolated:

Formula Rearrangement

Ex. D = m D v = m V = m

v D