Study Guide Chapter 11

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Study GuideChapter 11

• Forces
• Test Date April 3, 2009

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Vocabulary These are words you need to know
for your test.
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Speed

• A change in distance over time
• We can find speed by dividing distance traveled
  by the time it took

30 yards
15 seconds
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Velocity

• How fast an object is moving in a specific
  direction

10 mph
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Force

• A push or a pull

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Inertia

• The tendency of an object in motion to stay in
  motion, or of an object at rest to stay at rest

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Friction

• A force that works against motion

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Balanced Forces

• Forces that cancel each other out when acting
  together on one object

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Unbalanced Forces

• Forces that are not equal to each other
• Cause a change in motion

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Energy

• The ability to do work
• Energy is needed to apply force to move an object

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Potential Energy

• Stored energy that has the future ability, or
  potential, to do work
• While at rest, the roller coaster car has
  potential energy

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Kinetic Energy

• The energy of motion
• Once the coaster is moving, it has kinetic energy

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Simple machine

• A machine that has few parts and helps us to do
  work

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Inclined Plane

• A simple machine with just one part a flat,
  slanted surface

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Compound Machine

• Two or more simple machines combined

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Information You Need to Know
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Simple or Compound?

• Simple Machines
• Pulley
• See Saw
• Ramp
• Block Wedge
• Screw

• Compound Machines
• Bicycle
• Scissors
• Can opener
• Car engine

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Need to Know!!!!

• Inertia is the tendency for an object in motion
  to stay in motion or an object at rest to stay at
  rest
• Effort Force is the force used to do work
• Energy is the ability to do work
• Load is the object being moved by a simple machine

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Kinetic or Potential?

• Coaster up the ramp kinetic
• Coaster stops at top of hill potential
• Coaster races down ramp kinetic

• Kinetic Energy DOES WORK
• Potential Energy DOES NOT DO WORK

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• Essay Questions Be prepared to answer each of
  these questions in a well written short paragraph
  (means more than one sentence).

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• Light energy is important to all living things on
  Earth because plants use light energy from the
  sun to make food. Plants make food by changing
  light energy during photosynthesis. Animals use
  plants as an important food source.

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• Most rough surfaces cause greater friction
  because there are more bumps and cracks on the
  surface area for an object to come into contact
  with. The bumps in the rough surface grab hold of
  an object and keep it from moving as easily.
  Rubber is an example of a smooth surface that
  causes a lot of friction.

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• Fossil fuels are nonrenewable resources and they
  cause pollution. We can produce electricity using
  renewable resources such as the sun, wind, and
  water.