Transcript Lecture 8 - Empyrean Quest Publishers

My Power Point Presentations are ONLINE!
at: www.empyreanquest.com/perspectives.htm
1. Use internet Explorer.
2. A fast connection helps, as some of the
art is in very large files.
3. Make sure you activate Active X
--ignore warnings.
FROM NOTES: Newton's Accomplishments:
1. Observed first spectrum with prism.
2. Developed calculus to explain gravity and
Kepler's planetary motion.
3. Developed his three 'laws' of motion.
I. Objects continue at the same velocity,
unless acted on by an unbalanced force.
II. F = ma (Weight vs mass)
III. For every force there is an equal and
opposite force acting back on the actor.
4. The Universal Law of Gravitation
F = G m1m2/d2.
Gravity is a weak force (balloon demo).
5. Tidal Force:
a. Tides on earth oceans.
b. can break apart satellites.
6. Orbits.
7. Center of Mass.
8. Reflecting (Newtonian) telescope with a mirror
Observed first spectrum of the sun with a prism
Spectrum = spread of wavelengths
of light
Developed calculus to explain gravity and
Kepler's planetary motion
Newton’s three 'laws' of motion
—they get at the cause of changes in motion:
force.
Quotes from
Principia Mathematica:
Q
1st Law: Objects continue at the same velocity,
unless acted on by a net force.
Velocity = speed plus direction
Acceleration = rate of change of
velocity
F= m a: force equals mass times acceleration
Mass is DIFFERENT from weight
Weight is the force of gravity
on an object = mg. Measured with
a spring scale. Would be different
on Mars or the Moon.
Mass, m, is a measure of inertia
and is the same throughout the
universe. Measured with a balance
anywhere, even on Mars or the
Moon.
.
Newton’s Third Law:
For every force
there is an equal
and opposite force
acting back on the actor
Rg = - Rb
Every force has a ‘soulmate’!
The Universal Law of Gravitation
F = G m1m2/d2.
Double the distance, ¼ the force.
Gravity is a weak force (balloon demo).
Dr. P. jumps off table,
but doesn’t fall to center
of the earth. Proving that
electric force between his
feet and the earth is
stronger than gravity.
Cavendish Balance—measures the strength of gravity,
Force between balls of mass m and M.
What is the direction of gravity?
Taken at the Mystery Spot in Santa Cruz:
Christa MacCauliffe
—teacher killed in first space shuttle disaster.
Is she weightless on the space shuttle? No it is ‘apparent
weightlessness.
Tidal Force: greater gravity tug on
one side than another. Examples:
a. Tides on earth’s oceans.
b. can break apart satellites.
Miranda—moon of Uranus, broken up by tidal force
or impact? Reformed by gravity.
To put something in orbit
it must be going escape velocity.
About 18,000 mph
Barycenter
= Center
of mass
Used to calculate motions
of collections of bodies.