Download RP 5.P.1 Force and Motion - NC Science Wiki

North Carolina Science Essential Standards
Resource Pack for Unit planning
Essential Standard:
5.P.1
Understand force, motion and the relationship between them.
5.P.1.1 Explain how factors such as gravity, friction, and change in mass affect the motion of objects.
5.P.1.2 Infer the motion of objects in terms of how far they travel in a certain amount of time and the direction in which
they travel.
5.P.1.3 Illustrate the motion of an object using a graph to show a change in position over a period of time.
5.P.1.4 Predict the effect of a given force or a change in mass on the motion of an object.
Vertical Strand Maps:
http://scnces.ncdpi.wikispaces.net/Strand+Maps
Online Atlas map http://strandmaps.dls.ucar.edu/?id=SMS-MAP-1357
http://strandmaps.dls.ucar.edu/?id=SMS-MAP-1372
North Carolina Unpacking:
http://scnces.ncdpi.wikispaces.net/Race+to+the+Top+Support+Tools
Framework for K-12 Science Education:
Core Idea PS2 Motion and Stability: Forces and Interactions
How can one explain and predict interactions between objects and within systems of objects?
Interactions between any two objects can cause changes in one or both of them. An understanding of the forces between objects
is important for describing how their motions change, as well as for predicting stability or instability in systems at any scale. All
forces between objects arise from a few types of interactions: gravity, electromagnetism, and the strong and weak nuclear
interactions.
PS2.A: FORCES AND MOTION
How can one predict an object’s continued motion, changes in motion, or stability?
Interactions of an object with another object can be explained and predicted using the concept of forces, which can cause a
change in motion of one or both of the interacting objects. An individual force acts on one particular object and is described by
its strength and direction. The strengths of forces can be measured and their values compared. What happens when a force is
applied to an object depends not only on that force but also on all the other forces acting on that object. A static object typically
has multiple forces acting on it, but they sum to zero. If the total (vector sum) force on an object is not zero, however, its motion
will change. Sometimes forces on an object can also change its shape or orientation. For any pair of interacting objects, the
force exerted by the first object on the second object is equal in strength to the force that the second object exerts on the first but
in the opposite direction (Newton’s third law). At the macroscale, the motion of an object subject to forces is governed by
Newton’s second law of motion. Under everyday circumstances, the mathematical expression of this law in the form F = ma
(total force = mass times acceleration) accurately predicts changes in the motion of a single macroscopic object of a given mass
due to the total force on it. But at speeds close to the speed of light, the second law is not applicable without modification. Nor
does it apply to objects at the molecular, atomic, and subatomic scales, or to an object whose mass is changing at the same time
as its speed.
An understanding of the forces between objects is important for describing how their motions change,
as well as for predicting stability or instability in systems at any scale.
For speeds that are small compared with the speed of light, the momentum of an object is defined as its mass times its velocity.
For any system of interacting objects, the total momentum within the system changes only due to transfer of momentum into or
out of the system, either because of external forces acting on the system or because of matter flows. Within an isolated system
of interacting objects, any change in momentum of one object is balanced by an equal and oppositely directed change in the
total momentum of the other objects. Thus total momentum is a conserved quantity.
Grade Band Endpoints for PS2.A
By the end of grade 2. Objects pull or push each other when they collide or are connected. Pushes and pulls can have different
strengths and directions. Pushing or pulling on an object can change the speed or direction of its motion and can start or
stop it. An object sliding on a surface or sitting on a slope experiences a pull due to friction on the object due to the surface that
opposes the object’s motion.
By the end of grade 5. Each force acts on one particular object and has both a strength and a direction. An object at rest
typically has multiple forces acting on it, but they add to give zero net force on the object. Forces that do not sum to zero can
cause changes in the object’s speed or direction of motion. (Boundary: Qualitative and conceptual, but not quantitative addition
of forces are used at this level.) The patterns of an object’s motion in various situations can be observed and measured; when
past motion exhibits a regular pattern, future motion can be predicted from it. (Boundary: Technical terms, such as magnitude,
velocity, momentum, and vector quantity, are not introduced at this level, but the concept that some quantities need both size
and direction to be described is developed.)
PS2.B: TYPES OF INTERACTIONS
What underlying forces explain the variety of interactions observed?
All forces between objects arise from a few types of interactions: gravity, electromagnetism, and strong and weak nuclear
interactions. Collisions between objects involve forces between them that can change their motion. Any two objects in contact
also exert forces on each other that are electromagnetic in origin. These forces result from deformations of the objects’
substructures and the electric charges of the particles that form those substructures (e.g., a table supporting a book, friction
forces).
Gravitational, electric, and magnetic forces between a pair of objects do not require that they be in contact. These forces are
explained by force fields that contain energy and can transfer energy through space. These fields can be mapped by their effect
on a test object (mass, charge, or magnet, respectively).
Objects with mass are sources of gravitational fields and are affected by the gravitational fields of all other objects with mass.
Gravitational forces are always attractive. For two human-scale objects, these forces are too small to observe without sensitive
instrumentation. Gravitational interactions are nonnegligible, however, when very massive objects are involved. Thus the
gravitational force due to Earth, acting on an object near Earth’s surface, pulls that object toward the planet’s center. Newton’s
law of universal gravitation provides the mathematical model to describe and predict the effects of gravitational forces between
distant objects. These long-range gravitational interactions govern the evolution and maintenance of large-scale structures in the
universe (e.g., the solar system, galaxies) and the patterns of motion within them. Electric forces and magnetic forces are
different aspects of a single electromagnetic interaction. Such forces can be attractive or repulsive, depending on the relative
sign of the electric charges involved, the direction of current flow, and the orientation of magnets. The forces’ magnitudes
depend on the magnitudes of the charges, currents, and magnetic strengths as well as on the distances between the interacting
objects. All objects with electrical charge or magnetization are sources of electric or magnetic fields and can be affected by the
electric or magnetic fields of other such objects. Attraction and repulsion of electric charges at the atomic scale explain the
structure, properties, and transformations of matter and the contact forces between material objects (link to PS1.A and PS1.B).
Coulomb’s law provides the mathematical model to describe and predict the effects of electrostatic forces (relating to stationary
electric charges or fields) between distant objects. The strong and weak nuclear interactions are important inside atomic nuclei.
These short-range interactions determine nuclear sizes, stability, and rates of radioactive decay (see PS1.C).
Grade Band Endpoints for PS2.B
By the end of grade 2. When objects touch or collide, they push on one another and can change motion or shape.
By the end of grade 5. Objects in contact exert forces on each other (friction, elastic pushes and pulls). Electric, magnetic, and
gravitational forces between a pair of objects do not require that the objects be in contact—for example, magnets push or pull at
a distance. The sizes of the forces in each situation depend on the properties of the objects and their distances apart and, for
forces between two magnets, on their orientation relative to each other. The gravitational force of Earth acting on an object near
Earth’s surface pulls that object toward the planet’s center.
PS2.C: STABILITY AND INSTABILITY IN PHYSICAL SYSTEMS
Why are some physical systems more stable than others?
Events and processes in a system typically involve multiple interactions occurring simultaneously or in sequence. The system’s
stability or instability and its rate of evolution depend on the balance or imbalance among these multiple effects. A stable
system is one in which the internal and external forces are such that any small change results in forces that return the system to
its prior state (e.g., a weight hanging from a string). A system can be static but unstable, with any small change leading to forces
that tend to increase that change (e.g., a ball at the top of a hill). A system can be changing but have a stable repeating cycle of
changes, with regular patterns of change that allow predictions about the system’s future
(e.g., Earth orbiting the sun). And a stable system can appear to be unchanging when flows or processes within it are going on at
opposite but equal rates (e.g., water in a dam at a constant height but with water flowing in that offsets the water flowing out; a
person maintaining steady weight but eating food, burning calories, and excreting waste). Stability and instability in any system
depend on the balance of competing effects. A steady state of a complex system can be maintained through a set of feedback
mechanisms, but changes in conditions can move the system out of its range of stability (e.g., homeostasis breaks down at too
high or too low a temperature).
With no energy inputs, a system starting out in an unstable state will continue to change until it reaches a stable configuration
(e.g., the temperatures of hot and cold objects in contact). Viewed at a given scale, stable systems may appear static or dynamic.
Conditions and properties of the objects within a system affect the rates of energy transfer and thus how fast or slowly a process
occurs (e.g., heat conduction, the diffusion of particles in a fluid).
When a system has a great number of component pieces, one may not be able to predict much about its precise future. For such
systems (e.g., with very many colliding molecules), one can often predict average but not detailed properties and behaviors
(e.g., average temperature, motion, and rates of chemical change but not the trajectories of particular molecules).
Grade Band Endpoints for PS2.C
By the end of grade 2. Whether an object stays still or moves often depends on the effects of multiple pushes and pulls on it
(e.g., multiple players trying to pull an object in different directions). It is useful to investigate what pushes and pulls keep
something in place (e.g., a ball on a slope, a ladder leaning on a wall) as well as what makes something change or move.
By the end of grade 5. A system can change as it moves in one direction (e.g., a ball rolling down a hill), shifts back and forth
(e.g., a swinging pendulum), or goes through cyclical patterns (e.g., day and night). Examining how the forces on and within the
system change as it moves can help to explain the system’s patterns of change.
Science for All Americans:
MOTION
Motion is as much a part of the physical world as matter and energy are. Everything moves—atoms and
molecules; the stars, planets, and moons; the earth and its surface and everything on its surface; all living things,
and every part of living things. Nothing in the universe is at rest.
Since everything is moving, there is no fixed reference point against which the motion of things can be
described. All motion is relative to whatever point or object we choose. Thus, a parked bus has no motion with
reference to the earth's surface; but since the earth spins on its axis, the bus is moving about 1,000 miles per
hour around the center of the earth. If the bus is moving down the highway, then a person walking up the aisle
of the bus has one speed with reference to the bus, another with respect to the highway, and yet another with
respect to the earth's center. There is no point in space that can serve as a reference for what is actually moving.
Changes in motion—speeding up, slowing down, changing direction—are due to the effects of forces. Any
object maintains a constant speed and direction of motion unless an unbalanced outside force acts on it. When
an unbalanced force does act on an object, the object's motion changes. Depending on the direction of the force
relative to the direction of motion, the object may change its speed (a falling apple) or its direction of motion
(the moon in its curved orbit), or both (a fly ball).
The greater the amount of the unbalanced force, the more rapidly a given object's speed or direction of motion
changes; the more massive an object is, the less rapidly its speed or direction changes in response to any given
force. And whenever some thing A exerts a force on some thing B, B exerts an equally strong force back on A.
For example, iron nail A pulls on magnet B with the same amount of force as magnet B pulls on iron nail A—
but in the opposite direction. In most familiar situations, friction between surfaces brings forces into play that
complicate the description of motion, although the basic principles still apply.
Some complicated motions can be described most conveniently not in terms of forces directly but in summary
descriptions of the pattern of motion, such as vibrations and waves. Vibration involves parts of a system moving
back and forth in much the same place, so the motion can be summarized by how frequently it is repeated and
by how far a particle is displaced during a cycle. Another summary characteristic is the rate at which the
vibration, when left to itself, dies down as its energy dissipates.
Vibrations may set up a traveling disturbance that spreads away from its source. Examples of such
disturbances are sound, light, and earthquakes, which show some behavior very like that of familiar surface
waves on water—changing direction at boundaries between media, diffracting around corners, and mutually
interfering with one another in predictable ways. We therefore speak of sound waves, light waves, and so on,
and the mathematics of wave behavior is useful in describing all these phenomena. Wave behavior can also be
described in terms of how fast the disturbance propagates, and in terms of the distance between successive
peaks of the disturbance (the wavelength).
The observed wavelength of a wave depends in part upon the relative motion of the source of the wave with
respect to the observer. If the source is moving toward the observer (or vice versa), the wave is in effect
compressed and perceived as shorter; if the source and observer are moving farther apart, the wave is in effect
stretched out and perceived as longer. Both effects are evident in the apparent change in pitch of an automobile
horn as it passes the observer. These apparent shifts in wavelength therefore provide information about relative
motion. A particularly significant example of this shift is the change in the wavelength of light from stars and
galaxies. Because the light emitted from most of them shifts toward longer wavelengths (that is, toward the red
end of the spectrum), astronomers conclude that galaxies are all moving away from one another—and hence
that we are in a generally expanding universe.
Wavelength can greatly influence how a wave interacts with matter—how well it is transmitted, absorbed,
reflected, or diffracted. For example, the ways in which shock waves of different wavelengths travel through
and reflect from layers of rock are an important clue as to what the interior of the earth is like. The interaction
of electromagnetic waves with matter varies greatly with wavelength, both in how they are produced and in
what their effects are. Different but somewhat overlapping ranges have been given distinctive names: radio
waves, microwaves, radiant heat or infrared radiation, visible light, ultraviolet radiation,x rays, and gamma rays.
Materials that allow one range of wavelengths to pass through them may completely absorb others. For
example, some gases in the atmosphere, including carbon dioxide and water vapor, are transparent to much of
the incoming sunlight but not to the infrared radiation from the warmed surface of the earth. Consequently, heat
energy is trapped in the atmosphere. The temperature of the earth rises until its radiation output reaches
equilibrium with the radiation input from the sun. Another atmospheric gas, ozone, absorbs some of the
ultraviolet radiation in sunlight—the wavelengths that produce burning, tanning, and cancer in the skin of
human beings.
Even within the named ranges of electromagnetic radiation, different wavelengths interact with matter in
different ways. The most familiar example is that different wavelengths of visible light interact with our eyes
differently, giving us the sensation of different colors. Things appear to have different colors because they
reflect or scatter visible light of some wavelengths more than others, as in the case of plants that absorb blue
and red wavelengths and reflect only green and yellow. When the atmosphere scatters sunlight—which is a
mixture of all wavelengths—short-wavelength light (which gives us the sensation of blue) is scattered much
more by air molecules than long-wavelength (red) light is. The atmosphere, therefore, appears blue and the sun
seen through it by unscattered light appears reddened.
FORCES OF NATURE
The two kinds of forces we are commonly aware of are gravitational and electromagnetic.
Everything in the universe exerts gravitational forces on everything else, although the effects are readily
noticeable only when at least one very large mass is involved (such as a star or planet). Gravity is the force
behind the fall of rain, the power of rivers, the pulse of tides; it pulls the matter of planets and stars toward their
centers to form spheres, holds planets in orbit, and gathers cosmic dust together to form stars. Gravitational
forces are thought of as involving a gravitational field that affects space around any mass. The strength of the
field around an object is proportional to its mass and diminishes with distance from its center. For example, the
earth's pull on an individual will depend on whether the person is, say, on the beach or far out in space.
The electromagnetic forces acting within and between atoms are immensely stronger than the gravitational
forces acting between them. On an atomic scale, electric forces between oppositely charged protons and
electrons hold atoms and molecules together and thus are involved in all chemical reactions. On a larger scale,
these forces hold solid and liquid materials together and act between objects when they are in contact (for
example, the friction between a towel and a person's back, the impact of a bat on a ball). We usually do not
notice the electrical nature of many familiar forces because the nearly equal densities of positive and negative
electric charges in materials approximately neutralize each other's effects outside the material. But even a tiny
imbalance in these opposite charges will produce phenomena that range from electric sparks and clinging
clothes to lightning.
Depending on how many of the electric charges in them are free to move, materials show great differences in
how much they respond to electric forces. At one extreme, an electrically insulating material such as glass or
rubber does not ordinarily allow any passage of charges through it. At the other extreme, an electrically
conducting material such as copper will offer very little resistance to the motion of charges, so electric forces
acting on it readily produce a current of charges. (Most electrical wires are a combination of extremes: a very
good conductor covered by a very good insulator.) In fact, at very low temperatures, certain materials can
become superconductors, which offer zero resistance. In between low- and high-resistance materials are
semiconducting materials in which the ease with which charges move may vary greatly with subtle changes in
composition or conditions; these materials are used in transistors and computer chips to control electrical
signals. Water usually contains charged molecular fragments of dissolved impurities that are mobile, and so it is
a fairly good conductor.
Magnetic forces are very closely related to electric forces—the two can be thought of as different aspects of a
single electromagnetic force. Both are thought of as acting by means of fields: an electric charge has an electric
field in the space around it that affects other charges, and a magnet has a magnetic field around it that affects
other magnets. What is more, moving electric charges produce magnetic fields and are affected by magnetic
fields. This influence is the basis of many natural phenomena. For example, electric currents circulating in the
earth's core give the earth an extensive magnetic field, which we detect from the orientation of our compass
needles.
The interplay of electric and magnetic forces is also the basis of much technological design, such as electric
motors (in which currents produce motion), generators (in which motion produces currents), and television
tubes (in which a beam of moving electric charges is bent back and forth by a periodically changing magnetic
field). More generally, a changing electric field induces a magnetic field, and vice versa.
Other types of forces operate only at the subatomic scale. For example, the nuclear force that holds particles
together within the atomic nucleus is much stronger than the electric force, as is evident in the relatively great
amounts of energy released by nuclear interactions.
Benchmarks for Science Literacy:
Students should continue describing motion. And they can be more experimental and more quantitative as
their measurement skills sharpen. Determining the speed of fast things and slow things can present a challenge
that students will readily respond to. They also can work out for themselves some of the general relationships
between force and change of motion and internalize the notion of force as a push or pull of one thing on
another—whether rubber bands, magnets, or explosions.
Students should also increase their inventory of examples of periodic motion and perhaps devise ways of
measuring different rates of vibration. And students should use prisms to see that white light produces a whole
"rainbow" of colors. (The idea that white light is "made up of" different colors is difficult and should be
postponed to later grades.) There is nothing to be gained at this stage, however, from linking light to wave
motion. By the end of the 5th grade, students should know that
 Changes in speed or direction of motion are caused by forces. 4F/E1a
 The greater the force is, the greater the change in motion will be. The more massive an object is, the less
effect a given force will have. 4F/E1bc
 How fast things move differs greatly. Some things are so slow that their journey takes a long time;
others move too fast for people to even see them. 4F/E2
 Light travels and tends to maintain its direction of motion until it interacts with an object or material.
Light can be absorbed, redirected, bounced back, or allowed to pass through. 4F/E3** (ASL)
The main notion to convey here is that forces can act at a distance. Students should carry out
investigations to become familiar with the pushes and pulls of magnets and static electricity. The term
gravity may interfere with students' understanding because it often is used as an empty label for the
common (and ancient) notion of "natural motion" toward the earth. The important point is that the earth
pulls on objects.
 The earth's gravity pulls any object on or near the earth toward it without touching it. 4G/E1*
 Without touching them, a magnet pulls on all things made of iron and either pushes or pulls on other magnets.
4G/E2
 Without touching them, an object that has been electrically charged pulls on all other uncharged objects and
may either push or pull other charged objects. 4G/E3*
Big Ideas:
Nothing in the universe is at rest. Motion is as essential to understanding the physical world as matter
and energy are. All motion is relative. All motion is governed by the same basic rules.
Gravity is an attractive interaction. The earth's gravity pulls any object on or near the earth toward it
without touching it. A gravitational field is caused by an object with mass.
Changes in speed or direction of motion are caused by forces. The greater the force is, the greater the
change in motion will be. The more massive an object is, the less effect a given force will have.
The motion of an object can be described by its position, direction, motion and speed. Motion can be
measured and represented on graphs and through diagrams.
Essential Questions:
What is the origin of motion? How can we describe motion?
What is a force? What can forces do?
How can forces be used to make objects move, change direction, or stop?
How are force and motion connected? How can we describe their relationship?
How can we model the relationship of position, motion, direction and speed?
How is the motion of an object related to the size of the object and the amount of force that is applied to the object?
How are motion and gravity connected?
What is gravity? How does gravity ‘work’?
How does it affect things on the earth?
Enduring Understandings:
The position and motion of an object can be described accurately
An object’s position can be described only by locating it relative to another object..
A force is a push or pull (usually on an object).
Forces can cause objects to start moving, stop moving, or change direction.
An object’s size and the amount of force exerted on an object affect its speed and motion.
Gravity is the earth’s pull on things. Things on or near the earth are pulled toward it by the earth's gravity.
Identify Misconceptions:
Formative Assessment Probe Guide
http://scnces.ncdpi.wikispaces.net/Formative+Assessment+Probe+Alignment
Common Misconceptions:
http://www.physicsfirstmo.org/files/Misconceptions.pdf
https://msu.edu/~zenkcarl/PDF%20files/Portfolio_PDF/TE804_Assignment3.pdf
http://futurism.com/9-common-misconceptions-physics/
https://www.google.com/?gws_rd=ssl#q=Common+Misconceptions+about+force+and+motion
Annotated TEACHING Resources:
Slow the Ball
http://serc.carleton.edu/sp/mnstep/activities/27614.html
Students use their problem solving skills and knowledge of energy (kinetic and potential) to solve the
challenge of getting the longest roll time on their track.
Hurricanes 1: The Science of Hurricanes
http://www.sciencenetlinks.com/lessons.cfm?BenchmarkID=4&DocID=312
This lesson is the first of a two-part series on the science of hurricanes and the kinds of technology being
used to identify and track them. In this segment, students examine different scientific aspects of
hurricanes, all in an effort to begin to understand the nature of motion, particularly how changes in speed
or direction of motion are caused by forces.
Hurricanes 2: Tracking Hurricanes
http://www.sciencenetlinks.com/lessons.php?BenchmarkID=3&DocID=314
The purpose of this lesson is to examine the role of technology in identifying and tracking hurricanes. It is
the second in a two-part series on the science of hurricanes and the kinds of technology being used to
identify and track them. Students broaden their study by exploring how technology and science are used
today to identify, measure, and track powerful tropical storms to better warn and secure ...
Science in Focus: Force and Motion Workshops for Teachers
http://www.learner.org/workshops/force/
These eight free professional development workshops for K-8 teachers present science concepts in force
and motion. They are designed so that teachers come away with an understanding that will help them
engage their students in their own explorations. The workshops cover gravity, friction, air resistance,
magnetism, and tension through activities, discussions, and demonstrations.
Marble Roller Coaster engineering challenge
http://www.centexeweek.org/activities/marble-rollercoaster
In this activity students build a marble roller coaster to specific engineering design specifications using
only marbles, tape, and recycled file folders.
http://www.raft.net/ideas/Marble%20Rollercoaster.pdf
A more complex version incorporating additional materials.
http://www.msichicago.org/online-science/activities/activity-detail/activities/build-a-roller-coaster/
Here is a version using online directions and pipe insulation foam.
Motion Graphs
http://www.mysciencesite.com/motion_graphs.pdf
A reading that explains a variety of motion graphs.
The Moving Man
http://phet.colorado.edu/en/simulation/moving-man
Learn about position, velocity, and acceleration graphs. Move the little man back and forth with the
mouse and plot his motion.
Distance Time Graph Activity
http://graphs.mathwarehouse.com/distance-time-graph-activity.php
Students explore the relationship between distance and time as they move a space ship across the screen.
Motion and Forces at Learning Science.org
http://www.learningscience.org/psc2bmotionforces.htm
This is a collection of computer simulations that involve students in learning about force and motion
while they guide skateboarders, use machines, and more.
Science Kids – Physics for Kids
http://www.sciencekids.co.nz/physics.html
Discover the amazing world of physics for kids with our awesome range of free games, fun experiments,
science fair projects, interesting facts, amazing videos, quizzes and more!
Real World Physics Problems
http://www.real-world-physics-problems.com/physics-for-kids.html
For kids, the objects which are naturally the most interesting to them are toys.
Toys often involve a lot of physics just by how they work. Working with toys students can start to get a
feel for how it works, and learn all the tricks to get the maximum entertainment out of it. And if the toy
demonstrates a principle (or two) of physics then it will be these principles that they get a feel for.
Physics4Kids
http://www.physics4kids.com/files/motion_intro.html
Rader’s site that explains force, motion, gravity and more to kids in easy-to-understand language.
NCES 5P1 Livebinder
A livebinder dedicated to grade 5 Force and motion.
http://www.livebinders.com/play/play?id=478147
Video Resources:
Bill Nye on Motion
http://www.gamequarium.org/cgi-bin/search/linfo.cgi?id=8442
Bill Nye on Gravity
http://www.gamequarium.org/cgi-bin/search/linfo.cgi?id=7895
Text Resources:
Physics4Kids
http://www.physics4kids.com/files/motion_intro.html
Rader’s site that explains force, motion, gravity and more to kids in simple language.
Color Me Physics
http://www.aps.org/programs/education/k8/
Coloring and activity books featuring physics and physicists.
Ducksters Physics for Kids
http://www.ducksters.com/science/physics/
This site has readings that explore many physics topics. It also includes diagrams that help younger
students to grasp basic concepts.
Terminology:
gravity mass
position
friction
axis
force
push
pull
motion
speed
position
direction
Writing Prompts:
1. Write an essay describing three pieces of playground equipment (swing, teeter-totter, slide,
monkey bars). Explain how each piece of equipment works.
2. Some people think school buses ought to have seat belts. Do you agree with this, or not? Write an
essay explaining your opinion and your reasoning.
3. Write an essay explaining the importance of car seats for young children.
4. Should police be permitted to speed whenever and wherever they must in order to apprehend a
criminal? Explain what you think about this and why.
5. If you were building an amusement park, what three rides would you think you absolutely ‘must’
have in order to keep your patrons satisfied? Write an essay explaining the three rides and why
you think they are essential to a successful amusement park.