Transcript Linking Asteroids and Meteorites through Reflectance

Introduction to Physical Science
Monday, Wednesday, Thursday
Tom Burbine
[email protected]
Quiz tomorrow
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Covers everything up to today
I would know:
Order of the planets
speed = distance/time
acceleration = ∆velocity/time
Newton’s three laws of motion
force = mass*acceleration
1 km = 1,000 meters
1 kg = 1,000 grams
Isaac Newton (1642-1727)
• One of the most influential people in human history.
• His 1687 publication of the Philosophiæ Naturalis
Principia Mathematica (usually called the Principia)
is considered to be among the most influential
books in the history of science
• The book described universal gravitation and the
three laws of motion
• Newton showed that the motions of objects on Earth
and of celestial bodies are governed by the same set
of natural laws
Isaac Newton
• Newton built the first practical reflecting
telescope and developed a theory of color based
on the observation that a prism decomposes white
light into many colors
• In mathematics, Newton shares the credit with
Gottfried Leibniz for the development of the
differential and integral calculus
Isaac Newton
• Supposedly saw an apple fall to the ground
• He then understood that gravity was universal,
meaning it affected both the planets and us on
Earth
• Came up with 3 Laws of Motion
Force
• Force – anything that can cause a body to change
velocity
Gravity
• Gravity is a natural phenomenon by which objects
with mass attract one another.
Newton’s
st
1
Law
• In the absence of a net (overall) force acting upon
it, an object moves with a constant velocity
• An object at rest remains at rest
• An object in motion tends to remain in motion
unless a force is acting upon it
Why do things on Earth not
remain in motion?
Why do things on Earth not
remain in motion?
• Friction
Newton’s
nd
2
Law
• Force = mass x acceleration
• Units of Force kgm/s2 = newton
Newton
• A Newton is equal to the amount of force required
to accelerate a mass of one kilogram at a rate of
one meter per second per second
How much do you weigh?
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So much do you weigh
Say your mass is 100 kg
F = 100 kg x 9.8 m/s2
F = 980 Newtons
• 9.8 m/s2 is the acceleration of gravity on Earth
• This is the acceleration due to the Earth’s
gravitational field
F = ma
• F = ma
• a = F/m
• m = F/a
Question
• If you apply the same force to two separate carts,
one with a mass of 1 kg and one with a mass of
2kg. Which cart will accelerate more?
Answer:
• If you apply the same force to two separate carts,
one with a mass of 1 kg and one with a mass of
2kg. Which cart will accelerate more?
• The 1 kg cart will accelerate twice as much
Newton’s
rd
3
Law
• For any force, there is an equal and opposite
reaction force
• Gravity is holding you on the ground
• The ground is also pushing back up on you with
the same amount of force
Action and Reaction
• Action: Object A exerts a force on object B
• Reaction: Object B exerts a force on object A
http://www.vshiksha.com/system/files/u1/pslvc6-rocket.jpg
Question:
• Which pulls harder, the Moon on Earth, or Earth
on the Moon?
Answer:
• Which pulls harder, the Moon on Earth, or Earth
on the Moon?
• The same
Question:
• A bus and a bug have a collision. The force of the
bus on the bug splatters all over the windshield.
• Is the corresponding force on the bus greater, less,
or the same?
• Is the resulting deceleration of the bus greater
than, less than, or the same as that of the bug?
Answer:
• A bus and a bug have a collision. The force of the
bus on the bug splatters all over the windshield.
• Is the corresponding force on the bus greater, less,
or the same?
• The same
• Is the resulting deceleration of the bus greater
than, less than, or the same as that of the bug?
• Less because the masses are different (a = F/m)
Activities
• http://www.lth3.k12.il.us/tworivers/Pet%20Projec
ts/Pam%20Winterroth/pam%20winterroth's%20fi
nal%20project/Newton's%20laws%20of%20moti
on%20activities%20page.html
Homework
• http://www.youtube.com/watch?v=DI3rPT_9rW0
Any Questions?