Physical Science Physics

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Physical SciencePhysics

• OGT Prep

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Newtons Laws of Motion
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Newtons 1st Law

• (The Law of Inertia)
• An object at rest tends to stay at rest and an
  object in motion tends to stay in motion with the
  same speed and in the same direction unless acted
  upon by an unbalanced force

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1st Law Example

• Why is it so important to wear a seatbelt?
• Seat belts are used to provide safety for
  passengers whose motion is governed by Newton's
  laws. The seat belt provides the unbalanced force
  which brings you from a state of motion to a
  state of rest safely.

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Newtons 2nd Law

• The second law states that the acceleration of
  an object is dependent upon two variables - the
  net force acting upon the object and the mass of
  the object.
• Force Mass x Acceleration
• F M x a

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2nd Law Example

• Picture a big car and a small car. The bigger car
  obviously has more mass than the small car. If
  you give them the same force (the same push or
  pull), wont the big car move (accelerate) less?

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Newtons 3rd Law

• For every action, there is an equal (in size)
  and opposite (in direction) reaction force

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3rd Law Example

• An unfortunate bug strikes the windshield of a
  bus. The bug hit the windshield and the
  windshield hit the bug. Which of the two forces
  is greater the force on the bug or
• the force on the bus?

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Key Terms

• Force any push or pull
• Friction force which resists motion or
  attempted motion
• Weight the force due to gravity on a body
  (object)

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Law of Conservation of Energy

• In any physical or chemical change, energy is
  neither created nor destroyed
• It can only be transformed from
• one form of energy to another

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Energy

• Potential Energy stored energy. The energy is
  stored by doing work against a force such as
  gravity, a spring in a clockwork motor, or even
  an electromagnetic field.
• energy of position
• Kinetic Energy energy that a body possesses as a
  result of its motion.
• defined as work needed to accelerate a body from
  rest to a velocity
• - energy of motion

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Potential Energy

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Potential/Kinetic Energy
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Physical ScienceChemistry
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Physical and Chemical Properties of substances

• Physical Properties
• Can be observed w/o changing the identity of the
  substance
• Density
• Melting point
• Boiling point
• Color
• Mass

• Chemical Properties
• Describes how substances change into new
  substances either by combining w/ other elements
  or breaking apart into new substances
• Flammability
• Reactivity

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Physical and Chemical Changes

• Physical Changes
• Phase changes
• Freezing, melting, boiling
• Dissolving
• Can be reversed

• Chemical Changes
• Change in color or odor
• Production of sound, heat, or light
• Cannot be reversed without LOTS of energy

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Important terms in Chemistry

• Elements substance that cannot be separated or
  broken down into simpler substances by chemical
  means
• Protons subatomic particle with positive
  charge, mass of 1. Located in the nucleus of an
  atom
• Neutrons subatomic particle with no charge,
  mass of 1. Located in the nucleus of an atom
• Electrons subatomic particle with negative
  charge, has no mass

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Atomic Number
Symbol
Element Name
Atomic Mass
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Isotopes

• Atoms of the same element may have different
  numbers of neutrons. This causes different masses
  (atomic mass) BUT has no effect on charge.
• For example, all carbon atoms have 6 protons
  (atomic number is 6). The number of electrons
  depends on the charge and the number of neutrons
  depends on the atomic mass. C-14 has 6 protons
  and 8 neutrons.

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Ions
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Common Question

• How many protons, neutrons, or electrons are in
  the following element if it is 1 in charge

30 Zn Zinc 65.409
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Experiments in Chemistry

• Safety is always number one concern!!
• Goggles are worn for every experiment
• Common OGT experiments include experimenting with
  Acids and Bases

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Acids, Bases, and the pH scale

• pH is measurement of a liquid to determine if it
  is acidic, basic, or neutral.
• The scale goes from 0-14
• Low numbers (0-6) are Acidic
• High numbers (8-14) are Basic
• 7 is Neutral and is the pH of pure water

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Acids and Bases

• Acids
• Low pH (0-6)
• Sour Taste
• Conduct electric current
• Corrosive
• Can damage materials and skin
• Examples
• Lemon juice
• Stomach acid

• Bases
• High pH (8-14)
• Bitter Taste
• Very slippery feeling
• Conduct electric current
• Can damage materials and skin
• Examples
• Soap, many cleaners
• Fertilizer
• Milk