ATOMS & SPEED (Homework 2 to be worked but not turned
in)
(1-15-10)
Diameter= 0.5 to 2.5 x 10-8 cm (which is scientific notation, i.e., “economical”)
Scientific notation General (expanded) notation)
1 x 10-8 cm = ____________________________
How many inches is 1 x 10-8 cm? (1in = 2.54cm; 0.394in = 1cm)
Mass proton= 1.672 x 10-24 g
electron= 9.108 x 10-28 g
“Mole”= 6.02 x 1023 atoms of an element.
The atomic weight expressed in grams of an element will contain a mole of atoms
Element Mass of 1 mole
Li _____________
Ru _____________
1 mole of Ru is how many ounces? (1 oz = 28.35 g; 1 g = 0.0353 oz)
Speed of Light (in vacuum)
General Scientific
186,000 mi/s = _______________________
_____________________ = 3 x 1010 cm/s
LAWS OF THERMODYNAMICS
1ST LAW
ENERGY
MAY BE TRANSFORMED FROM ONE TYPE TO ANOTHER, BUT IT IS NEVER CREATED OR
DESTROYED.
EXAMPLES
OF ENERGY:
HEAT,
LIGHT, KINETIC ENERGY, ELECTRICAL ENERGY,
POTENTIAL
ENERGY OF FOSSIL FUELS, FOOD, GRAVITY
2ND LAW
“HEAT
CANNOT BE COMPLETELY CONVERTED TO WORK.”
“NO
ENERGY TRANSFORMATION IS 100% EFFICIENT.”
“ENERGY
CAN BE CONVERTED FROM ONE FORM TO
ANOTHER, BUT IN ALL CONVERSIONS THERE
IS FORMATION OF SOME ‘LOW QUALITY’, ‘NON-USABLE’
HEAT.”
“UNIVERSE
RUNS DOWN AS ENERGY IS DISPERSED TO
UNIFORM (LOW QUALITY) HEAT ENERGY.”
“ALL
SYSTEMS TEND TO BECOME RANDOM (OR DISPERSED)
ON THEIR OWN.”
FROM
FOOD & FOSSIL FUELS, ABOUT 40-45% OF ENERGY IS EXTRACTED AND USED.
1ST LAW
EVERY
OBJECT PERSISTS IN A STATE OF
2ND LAW
THE
CHANGE IN VELOCITY (=ACCELERATION) WITH WHICH AN OBJECT MOVES IS DIRECTLY
PROPORTIONAL TO THE MAGNITUDE OF THE FORCE APPLIED TO THE OBJECT AND INVERSELY
PROPORTIONAL TO THE MASS OF AN OBJECT.
a =
F/m or F = m ´ a
3RD LAW
EVERY
FORCE OR ACTION HAS AN EQUAL AND OPPOSITE REACTION (LAW OF CONSERVATION OF
MOMENTUM)
LAW OF UNIVERSAL
GRAVITATION
EVERY
OBJECT IN THE UNIVERSE ATTRACTS EVERY OTHER OBJECT WITH A FORCE DIRECTLY
PROPORTIONAL TO THE PRODUCT OF THEIR MASS AND INVERSELY PROPORTIONAL TO THE
SQUARE OF THE DISTANCE BETWEEN THEM.
F =
G ´ (m1
´ m2)
r2