Download Energy and Work - Stanley Teacher Prep

Physical Science
What background knowledge do
you need to get the joke?
• What gravity does.
• That “keeps me down” means bums you out!
What is Physical Science
• Physics: the science of
matter and energy and
their interactions
– Sciences such as physics,
chemistry, astronomy,
– studies of matter,
electricity, magnetism,
sound, and light
– designed to observe
behaviors of physical
objects
Matter Topics
• States of Matter
• Changes in state of matter
• Behaviors of Gasses and Fluids
Matter - anything that takes up
space and has mass
Four States of Matter
• Solid
• Liquid
• Gas
• Plasma
» Mass - amount of
matter in an object
Amorphous solids
• Amorphous without a definite
form
– Some scientists think
they should be
classified as very
thick liquids
Chemistry Topics
• Atoms
• Elements
• Mixtures vs
Compounds*
• Polarity of Water
– Chemical Bonds
– Acids and Bases
Thermal Expansion - matter expands
as it warms, contracts as it cools
• As heat a substance,
give more E to
molecules
• As cool a substance,
take away molecule’s
E
Energy and Forces Topics
• Energy and Work
• Motion and Forces
• Newton’s 3 Laws
Energy-An Agent of Change
•
When an object can
change its environment, it
has energy (e.g baseball
breaking window)
– Energy: ability to cause
change (E)
Two types of energy:
1. Kinetic Energy
2. Potential Energy
Kinetic Energy (KE)
• Kinetic energy: energy in
the form of motion
– E.g. spinning bicycle wheel,
sprinting, flying Frisbee
Potential Energy (PE)
• Potential energy: stored
energy
Conservation of Energy
• Law of conservation of
energy: energy is neither
created or destroyed, only
changes state
– As you move back and
forth, energy is converted
from kinetic to potential
back to kinetic energy
continuously
– So why does the swing
eventually stop?
What is work?
•
Work: transfer of
energy through
motion
– In order to take place,
force must be exerted
Force - push or pull
• Balanced forces - forces
on an object that are
equal in size and
opposite in direction
– Do not change an
object’s motion
• Unbalanced forces force that changes the
motion or position of an
object
– Cause it to accelerate
Motion - change in position
• Speed - distance
traveled in a certain
amount of time
– Rate of motion
Newton’s First Law - object moving at a constant
velocity keeps moving at that velocity until
acted upon by an unbalanced force
• Object in motion stays in motion
– E.g. Air hockey puck glided until hits
wall
• Object at rest stays at rest
– E.g. Hockey puck stays on ice until
hit it
• Also called law of inertia
• Inertia - tendency of an object to
resist changes in motion
Momentum - measures the
amount of inertia (mass x velocity)
• High velocity = more
momentum
• High mass = more
momentum
Friction
• Friction - force that
opposes motion between
two surfaces that are
touching each other
• Depends on:
– Type of surfaces
– Force pressing
surfaces together
Types of Friction
• Sliding friction - when
solids slide over each
other
– Strongest friction
• Rolling friction - when
objects roll over a
surface
– Medium strength
• Fluid friction - when
object moves through a
fluid
– Least strong
Steps of the Scientific Method
•
•
•
•
•
•
•
Observe
Question
Hypothesize
Experiment
Record Data
Analyze Data
Conclude
The
Science
Circle
Experiment and
Bloom’s Taxonomy:
Science’s Natural
Progression