STUDY GUIDE – Science 1st Nine Weeks’ Exam
This 50 question multiple-choice exam is worth 200 points and will be given on Thursday, October 6,
2011. It will cover material from Chapters 1,5,6,9, and 17 in the Holt textbook and Lessons 1-7 in the
AMSTI book.
Study Group will be held Thursday starting at 7:15 in the Lunchroom.
Chapter 1: The World of Physical Science
Define the following terms:
hypothesis: explanation based on research and observations; it must be testable
physics: branch of physical science dealing with how energy affects matter
matter: “stuff” everything is made of – all matter has energy because atomic particles are
always in motion
law: summary of many experimental results and observations; it tells you what happens but
not why it happens
theory: explanation that ties together many hypotheses and observations; can be used to
predict outcomes in the future
List the steps to the scientific method: as outlined in Figure 1 on page 12.
1. Make observations, which leads to
2. Ask questions, which leads to
3. Form a hypothesis, which is your best answer to the question
4. Test the hypothesis by conducting an experiment
5. Analyze the results of the experiment including graphing the data
6. Draw conclusions and indicate whether or not the hypothesis should be accepted or
rejected.
7. Communicate your results to others
List the base SI units for measuring:
Length: meter, mass: kilogram and volume: cubic centimeter (solids and some gases) or liter
(liquids and some gases)
What is the difference between a law and a theory? Theories explain what happens and can be
used to predict outcomes – theories will change over time as more observations are made.
Laws summarize experimental results and observations. Laws tell what happens but not why
things happen. Laws are fact and do not change.
Why is the SI (International System of Units) used by scientists throughout the world?
The SI system is easy to use because its units are based on 10, which makes converting to
bigger or smaller units much easier. The SI system also uses a standard set of prefixes and
provides a common system of measurement throughout the world.
Chapter 5: Matter in Motion and AMSTI Lessons 5 and 6 and their readings from the EMM book.
Define friction: force that opposes motion when two surfaces are in direct contact. Heat is a by
product of friction.
List the ways that friction affects motion by completing this chart
How Friction is helpful
Car brakes provide stopping power
Allows us to walk on many surfaces
Allows us to write with a pencil
How Friction is harmful
Wears down engine parts
Erosion – removal of soil
Produces heat in an engine, which can warp
parts
Define net force: More than one force can act on an object at once. The net force is the
combination of all forces acting on an object.
Draw an example and explain how to determine net force when all forces acting on the object are in
the same direction.
If one person pushed to the right with a force of 8 Newtons, and the other person also pushed
to the right with a force of 6 Newtons, then the net force on the book would be 14 Newtons
toward the right. In this case the two forces would complement each other, rather than tending
to cancel each other. Here is a picture of that:
This object will move as if it had a single force of 14 Newtons pushing on it toward the right.
Draw an example and explain how to determine net force when the forces acting on the object are in
the different directions.
If one person pushed the book with a force of 20 Newtons toward the left, and the other
person pushed the book with a force of 18 Newtons toward the right, then that the net force
would be 2 Newtons in size and directed toward the left. Here is a picture showing those
forces:
As you can see, the net force is aimed toward the left. This object will move as if it had a
single force of 2 Newtons pushing on it toward the left.
If the two people pushing on the book each push with the same strength, again one person
pushing toward the left and the other pushing toward the right. In this case the two forces
would exactly cancel each other out. The net force on the book would be 0 Newtons. Here is a
picture of that situation:
When two or more forces cancel each other out to create a net force of 0 as in the above
diagram, we say that the forces on the object are balanced. We also say under these
conditions that the forces on the object are in equilibrium. Under such conditions the object
will not accelerate. That is, the velocity of the object will not change.
What are the differences between mass and weight?
Mass is the measure of the amount of matter (stuff) in an object and remains constant.
Weight is a measure of gravitational force on an object. While mass = weight on the surface of
the Earth, it will be different in space, where gravity’s strength is different.
The metric units of mass are kilogram (kg) and gram (g) and for weight it is the Newton (N).
Chapter 6: Forces and Motion and AMSTI Lesson 7 and its readings
What is air resistance and what factors affect it? Air resistance is the force that opposes motion
through air. It is affected by the size, shape and speed of the object, but not by what it is
made out of.
What two motions combine to cause “orbital motion”? Forward motion combines with free fall to
create orbital motion. Free fall is motion with no acceleration other than that provided by
gravity.
What is inertia and how is it related to the weight of an object? Inertia is the tendency of an object
to keep on doing what is has been doing. On Earth, the greater the mass (and therefore,
weight) the greater the inertia. It takes more force to get a dump truck moving (or to stop it)
than to get a motorcycle moving (or stopped) because the dump truck has more mass and
therefore more inertia.
How does projectile motion affect objects thrown horizontally and what forces affect the object?
If the object is moving at a constant speed in the forward direction it will also be pulled
downward by gravitational force so it will curve and eventually fall to the ground.
Chapter 9: Energy and Energy Resources and AMSTI Lessons 2, 3, 4 and 7
What kind of energy is the food you eat? Food is a form of chemical energy. What kind of energy
does your body convert this energy into? The chemical energy in food is converted at the cellular
level into kinetic energy (the energy of motion).
Define the following:
Potential energy: Energy stored by an object due to its position, shape or condition.
Kinetic energy: Energy of an object due to its motion
Gravitational potential energy: Stored energy due to an object’s position. It is calculated by
multiplying the object’s height by its weight.
Mechanical energy: The amount of work and object can do based on its total energy of motion
(kinetic) and position (potential)
State the Law of Conservation of Energy in your own words. Energy can not be created or
destroyed, but can be changed (converted) from one form into another. In the real world we
must account for the fact that some heat energy is lost to outer space.
What type of machine converts kinetic energy into electrical energy? Electric generators convert
the kinetic energy of a rotating coil into electrical energy.
Describe all the energy conversion and where they occur when you use a battery to power a light
bulb.
When a complete circuit is in place, a battery’s chemical energy is converted into electrical
energy which flows through wires to the light bulb where it is converted into both heat
(thermal) energy and light energy.
Chapter 17: Introduction to Electricity and AMSTI Lessons 2, 3, 4, and 7 and their readings
What are the tiny particles that make up all matter? All matter is made up of atoms. Atoms have
positively charged protons and non-charged neutrons in the nucleus and negatively charged
electrons orbiting around the nucleus.
Define the following:
Electric field: Space around a charged object that causes another charged object to experience
an electric force.
Electrode: Solid part of a battery where electric current enters and/or leaves the battery cell.
We made a wet-cell battery using a cooper electrode (positive) and a zinc electrode (negative).
Electrolyte: Liquid solution or paste inside a battery. Its molecules spontaneously separate
into + and – charged ions. Our wet cell battery used copper sulfate as its electrolyte.
Electric Power: Rate at which electrical energy is converted into other forms of energy. It is
calculated by this formula: P = V x I or Power = Voltage x Current
Electric discharge: Release of static electricity stored in a source. Lightning is an example of
the electric discharge of static electricity that was stored in a cloud.
Circuit breaker: A switch that automatically opens if the current flowing through wires is too
high and can cause a fire.
Voltage: The potential difference between two points in a circuit. It is a measure of how much
work is needed to move the charge from point to point. You can think of it as the amount of
energy released as the charge moves along the path of the current. It is measured in volts.
Resistance: Opposition to flow. The resistance determines how much current will flow through
a component in the circuit. It is measured in ohms (
).
Current: The rate electric charges pass a given point; flow. It is measured in amps
What does the size of an electric current depend upon? Voltage – the greater the voltage the
greater the current flowing through the wire.
What materials make good conductors? Conductors allow electric charges to flow freely and
include materials such as the metals copper, aluminum and mercury.
What materials make good insulators? Insulators restrict electric charges from freely flowing and
include materials such as plastic, rubber, glass, wood and air.
What type of energy is found in a battery? Batteries contain chemical energy.
What can be done to lower the electrical resistance of a wire? To lower resistance is to increase
the flow of electrons and can be done by using thicker wire, shorter wire, lower temperatures
and using a material that is a good conductor. To increase resistance or to reduce flow you
would use thinner wire, longer wire, higher temperatures and materials that have insulating
properties.
What do the markings such as 60W or 100W on a light bulb tell you about the light generated by the
bulb? W is a power rating – the higher the number the brighter the light from the bulb.
Additional AMSTI material: From Lessons 1-7 and associated readings
Define the following and tell on which axis this variable will be plotted on:
Dependent variable: Data that depends on the independent variable is known as the dependent
variable and it is what you measure during the experiment. In Lesson 7 the dependent
variable was how many washers your motor could lift. The dependent variable is plotted along
the y-axis.
Independent variable: The manipulated, variable that you control. In Lesson 7 the independent
variables included number of batteries, how you connected them and where the string was
attached to the motor. The independent variable is plotted on the x-axis.
What were the important discoveries of?
Galileo Galilei: The Sun is the center of our solar system and he used his improved telescope
to discover the four moons of Jupiter.
Alessandro Volta: Built the first electric battery over 200 years ago
Robert Hooke: Wrote the law about the nature of elastic force known as Hooke’s Law. He also
coined the term “cells” to name what he saw under his microscope.
Isaac Newton: Wrote the Law of Universal Gravitation and the Three Laws of Motion.
Restate Hooke’s Law: Force is directly proportional to the stretch of a spring.
Which type of battery connection will provide your motor with the most energy? Series connections
provide the most energy because the voltage of the batteries is cumulative.
You will be asked on the exam to make several types of calculations. The formulas will be provided,
but you must know how to use them and what units go along with the answers.
Using Ohm’s Law: Voltage = Current x resistance - correct unit: volts
Work the Math Focus problems on page 491. The Math Focus shows you how to work the sample
problems and then gives three practice problems.