Volume 1, Issue 3
Motion and Forces
What’s the ‘big idea’?
The introduction to the big idea (from our Program of Studies) states:
Whether observing airplanes, baseballs, planets, or people, the motion of all
bodies is governed by the same basic rules. In the elementary years of conceptual
development, students need multiple opportunities to experience, observe, and
describe (in words and pictures) motion, including factors (e.g., pushing, pulling)
that affect motion.
When you look at the Combined Curriculum Document (on the KDE web at:
hing+Tools/Combined+Curriculum+Documents/default.htm ) you notice that beyond ‘pushes and
pulls’ and ‘change in position over time,’ this big idea encompasses other ‘subtopics’
such as relative position, sound and magnetism. The key to knowing ‘how far to go’
with the ideas for your particular level is to really begin with the “Enduring
Understandings” column to make sense of what is important for students to ‘leave’ your
class familiar with and understanding.
The truly important thing to keep in mind when teaching and exploring these concepts
with students is that in order for the ideas to be internalized and made sense of, this big
idea must be centered on engaging with materials and investigating...it must be HANDS
ON and minds on! And you don’t need elaborate resources or materials. Many of the
concepts can be explored using things you probably already have---rulers (especially
the ones with the grooves down the middle—they can be used as ramps and to
measure!), marbles or other spheres, graph paper, stopwatches/timers, toy cars, balls,
an assortment of magnets—just to name a few!
Because this is such a ‘hands on’ big idea, it will be critical to develop students’
observational, measurement and record keeping skills. Students will need to learn to
record ‘motion’—whether it be in the form of ‘T-charts’ to chart position against time, the
use of number lines to describe motion and direction of motion, simple diagrams to
chart the position of an ‘observer’ related to described motion, or other diagrams to
record the path of moving objects/forces acting on an object. This is such a critical
element to their learning! They must have data from which to draw conclusions, make
inferences and predictions, and use as ‘evidence’ for their reasoning.
The Benchmarks for Science Literacy explain how to develop the conceptions of
motions and forces for K-2 and 3-5. (You can read the sections completely at:
Look for “Motions” and “Forces of Nature” in the table of contents.
What are the common misconceptions that young students have around the
concepts or motion and forces?
(from Operation Physics: http://amasci.com/miscon/opphys.html )
1. The only "natural" motion is for an object to be at rest.
2. If an object is at rest, no forces are acting on the object.
3. Only animate objects can exert a force. Thus, if an object is at rest on a table, no
forces are acting upon it.
4. Force is a property of an object. An object has force and when it runs out of force
it stops moving.
5. The motion of an object is always in the direction of the net force applied to the
6. Large objects exert a greater force than small objects.
7. A force is needed to keep an object moving with a constant speed.
8. Friction always hinders motion. Thus, you always want to eliminate friction.
9. Frictional forces are due to irregularities in surfaces moving past each other.
10. Rocket propulsion is due to exhaust gases pushing on something behind the
11. Time is defined in terms of its measurement.
12. The location of an object can be described by stating its distance from a given
point (ignoring direction).
13. The terms distance and displacement are synonymous and may be used
interchangeably. Thus the distance an object travels and its displacement are
always the same.
How can I introduce students to motions and forces in a ‘real-life’ context?
One of the most successful and FUN units that I ever taught was “Take Me Out to the
Ballpark”—a unit that emphasized learning about relative position
and motion using the context of baseball. I taught it in the fall to
coincide with the World’s Series, but since it is almost ‘opening day’
for the season, it would make sense and be timely to do it in the
spring, too! (This is also a great unit for integrating every other
content area – if you would like some of the other ways I integrated,
just email me).
Some “Essential Questions” to go along with this unit or theme could include:
What does relative position have to do with baseball?
Why would it be important to be able to describe motion in a baseball game?
What do I need to know about forces to improve my baseball game?
Since this unit would not address ALL of the understandings/skills and concepts for the
big idea, here are some of the specific learning targets for this piece (adaptable for P-5).
Knowledge Skills/Reasoning Products
Know the meaning of Describe the position of Create diagrams to show
‘position’; know that words observable objects (from a positions/locations of
like left, right, behind, in personal perspective) objects
front of, near, far, etc.
describe position or location Describe the position of
observable objects from a
position other than my own
Identify tools for measuring Use a clock/stopwatch to
and match them with their measure time
Use meter sticks/rulers/tape
measures/trundle wheels to
Know that motion means a Collect data (time and Create motion charts and
change in position over distance) for a moving diagrams from data
time object collected or supplied
Determine the best way to
chart/graph motion data
Interpret simple motion
chart data/graphs into
words/sentences (e.g., that
graph shows that the ball
went 50 cm in 5 seconds,
the diagram shows that the
ball rolled 10 cm in the first
5 seconds, but only 5 cm in
the last 5 seconds—so the
ball was slowing down, etc.)
Identify a force as a push or Make inferences about the
pull strength of forces based on
Predict the motion of
objects given information
about the mass of the
object and the amount of
force to be applied
I began the unit by asking my students what they knew about a baseball diamond—how
was it set up, where were objects and people located, etc. By ‘sketching’ on the board
while they shared information about the ‘arrangement’ of the field, I began to get a feel
for how they could convey information about positions—near, far, left, right, behind, etc.
By assessing this ‘prior knowledge,’ I could determine where to begin.
We worked both with models (diagrams) and ‘real world’ baseball diamonds (outside).
We began by describing positions relative to ‘home plate’ (generally a typical
orientation), but then we would put ‘players’ out on the fields (both the diagrams and the
real one) and talk about our descriptions of the locations of objects. Were they always
the same? If I am on home base, how do I describe where 3rd base is? If I am in left
field, how do I describe where 3rd base is? etc. The understanding of ‘relative position’
is foundational to moving forward with being able to discuss motion/direction of motion.
Next, we began to develop a concept of motion—a change in position over time. We
talked about motion in a baseball game—what IS in motion during a game? How can
we describe those motions? We used meter sticks to measure distances and them
used stopwatches to record running times—encouraging some kids to run “fast”, some
to intentionally run more slowly, etc. We also timed ‘throws’—for example from home
plate to 1st base, etc. We charted and graphed this data to get a feel for how to
represent the data—and how to go backwards. If we saw charts or graphs like these,
then what did they really ‘show’ or ‘tell us’? For example, look at the chart that shows a
car moving over a period of seconds (below), what can we say about its motion? Is it
speeding up or traveling at a constant rate? Could you transfer this data into a t-chart?
Can you describe it using words?
(For some excellent examples, information creating/interpreting motion diagrams, go to:
(An online simulation to match motion with a graphical representation:
We explored motion further with balls—does the ‘mass’ of the ball affect how far it rolls
or can be thrown? Is there a relationship to force? How could we really test this?
These are just some of the concepts that you can begin to explore through the baseball
context. I found, too, that the girls were just as interested as the boys! By using this
context to really engage the students, they were able to pose so many of their OWN
questions about position, motion, and forces.
Some sample tasks/assessments for motion and forces:
NAEP item for grade 4: Relative Motion of 2 Vehicles (open response-like)
From the 2004 Kentucky Core Content Test:
From the 1999 KCCT:
Where can I find some quality resources for teaching about Motion and Forces?
A number of websites deal with the “Physics of Baseball.” Though they may present
ideas that go beyond what you would do with your students, there is some very
interesting information—and they may give you some new/better ideas.
The Science of Baseball - Exploratorium
The WhyFiles: The Science Behind the Headlines
The Science of Baseball (more suitable for upper elementary and beyond—but very
National Geographic’s Kids News: The Physics of Baseball (elementary feature article)
The Physics of Baseball
Physics of Baseball
Science NetLinks (http://www.sciencenetlinks.com/matrix.cfm )has a variety of
lesson plans aligned to our standards. Below are some that correlate to this Big Idea:
Making Objects Move (K-2)
Purpose: To identify ways to make objects move; to construct a structure that can be
used to move an object from one place to another.
Ramps 1: Let it Roll! (K-2)
Purpose: To explore and measure the rate of spherical objects rolling down a ramp.
Ramps 2: Ramp Builder (K-2)
Purpose: To plan, build, and test a ramp that allows objects to roll far.
Purpose: To explore the role of gravity in falling.
Yo-Yo Motion (3-5)
Purpose: To develop students' understanding of change of speed and the effect of
gravity through observations and explorations with a homemade yo-yo.
Hurricanes 1 (3-5)
Purpose: To introduce students to the science of hurricanes in an effort to highlight how
forces change the speed and direction of motion.
Magnets 1: Magnetic Pickups (3-5)
Purpose: Students will gain an understanding that certain materials are attracted to
magnets and some are not.
Magnets 2: How Strong is Your Magnet? (3-5)
Purpose: To experimentally measure the strength of a magnet and graph how the
strength changes as the distance from the magnet increases, and as the barrier
(masking tape) is built between the magnet and an iron object.
KET’s EncyloMedia has a number of video segments to support instruction for this big
idea. Log in, then do a search for “motion,” “forces,” “magnetism,” “sound,” etc.
Questions or comments? Contact: email@example.com