Physical Sciences K-8: Dynamics: Forces and Motion Units
A branch of mechanics that deals with forces and their relation primarily to motion but also sometimes to the equilibrium of bodies. Units are not listed in a prescribed order.
Newton's First Law & Inertia (10)
Lesson Plans:
A set of seven experiments on the Law of Inertia, developed by a team of scientists and educators in the UK. Each experiment has been classroom-tested and focuses on practical applications of the concepts to be presented. Contains full instructions for set-up, safety information, and tips for teachers.
Level: Grades 6-12
This unique lesson helps students understand that inertia is an inherent property of matter, while weight depends on gravity. Using simple and inexpensive objects, students make mass measurements without the use of gravity, similar to the measurements made aboard the Skylab space mission.
Level: Grades 8-12
Activities:
Cool classroom demo for illustrating inertia at rest. A dollar bill is placed between two soda bottles; the top bottle is filled with water. Upward/downward forces are balanced because the dollar acts as a sealant. Quickly removing the dollar bill creates a net unbalanced force on the water, which whooshes into the soda bottle below. Try teaming this teacher-led demo with the Pencil Drop below, which students could perform.
Level: Grades 6-12
A great companion to the "Dollar Bill Grab" above. This demo illustrates the same basic concept (Law of Inertia). If done correctly, it looks like a magic trick. Even if done incorrectly, it still demonstrates the idea of inertia at rest. Could be a good springboard for cooperative learning groups to discuss the meaning of net force, and what happens when net force is zero.
Level: Grades 6-12
What would happen if an object in circular motion suddenly loses its net centripetal force? Teachers can easily set up this demo to show students that Newton's Law of Inertia will govern the situation, and the object will fly off in a straight line tangential to the circular path.
Level: Grades 6-12
Content Support For Teachers:
Problem-Based Learning (PBL) is an instructional method that presents authentic, life-like situations to engage students in learning. Click here to read more about the pedagogical basis of PBL and how to implement it in the physics classroom. This site also features several PBL scenarios developed for introductory physics students (many are appropriate for high school).
Level: Secondary teachers
This chapter from The Book of Phyz offers curriculum support for teaching about the Law of Inertia. It features well-written background information for teachers, related activities and experiments.
Level: Secondary teachers
Student Tutorials:
Beginning students gain an in-depth, yet entertaining view of the background and applications of the Law of Inertia. Through animations and self-guided problems, this tutorial helps students understand the idea of unbalanced force and see that mass is a measure of the amount of inertia.
Level: Introductory Physics
Assessment:
A simulation-based problem to spark student discussion about inertia and force interactions. A puck traveling on a frictionless air hockey table is given a momentary push. What is the resulting path of its motion? Pair this applet with the one below on sustained push. Assesses student understanding of how resultant motion is affected by the type of force applied.
Level: Grades 6-12
A simulation-based problem that supplements the problem above on momentary push. A satellite is floating at constant velocity when its thrusters engage. The resulting path of its motion will differ from the example above. Assesses student understanding of how resultant motion is affected by a sustained force produced by thrust.
Level: Grades 6-12
Newton's Second Law & Net Force (7)
Lesson Plans:
This lesson plan for Grades 6-8, with printable student guide, is a great supplement to the PhET simulation Forces and Motion. The winner of a PhET "Gold Star", it was developed by an experienced teacher to provide explicit guidance for students as they use the simulation to investigate force interactions. We like it because it provides just the right amount of help to navigate the simulation, while also allowing students to construct their own meaning from the model.
Level: Grades 6-8
This archived lesson module challenges students to build a model spacecraft with certain constraints: as light as possible, yet strong enough to withstand three "launch-to-orbit" trips. Kids will be exposed to engineering design, the physics of thrust and drag, and using systems analysis to solve problems. All materials are readily available at hardware or grocery stores. Meets multiple national standards in science, mathematics, and language arts.
Level: Grades 6-9
Duration: Six Class Periods
Inertia is proportional to mass, weight is also proportional to mass, too, so both go together. The difference is that inertia is an inherent property of matter, while weight also depends on gravity.
Level: Grades 8-12
Duration: 30-40 minutes
Activities:
This experiment gives kids a concrete way to explore Newton's Second Law of Motion by doing timed trials on a "car" built out of wooden blocks, wood screws, fishing sinkers, rubber bands, and matchsticks. They can increase the mass of the car by adding sinkers and increase the propulsion by adding rubber bands.....they will discover that the distance traveled depends on the number of rubber bands and the mass of the block.
Level: Grades 6-12
Duration: One class period
This simulation lets students explore force interactions, motion graphs, and friction at a broad range of levels. Choose from 5 objects of different masses, select a wood or ice surface, then "push" the object on a straight path. You can display force vectors, free body diagrams, and graphs of position, acceleration, and velocity vs. time. Record your "push" and play it back to see the sum of forces. For more advanced students: set gravitation to mimic the Moon or Jupiter and watch the effects on static and kinetic friction!
Level: Grades 6-12
Content Support For Teachers:
Looking for a refresher on force interactions? This four-part tutorial features multiple diagrams, illustrations, interactive problem sets, and extras for teachers. It provides a concise exploration of types of forces, how to determine net force, and how to construct free-body diagrams to represent force interactions.
Level: Grades 7-8
Assessment:
It can be difficult for beginners to recognize different force interactions, especially since these concepts sometimes run counter to the student's intuition. This interactive assessment lets them practice in a self-directed environment. They view 11 common physical situations, then decide which forces are present. Afterward, they use a pull-down menu to view correct answers -- all accompanied by explanations.
Level: Grades 8-12
Duration: 15-20 minutes
Applications of Newton's Laws (11)
Lesson Plans:
This is Part 1 of a two-part multimedia unit on systems, approached from the framework of simple machines. It was developed to address the misconception of a machine as a collection of separate things. Instead, it presents the simple machine as a system to reinforce the concept of interaction.
Level: Grades 3-5
Duration: 1-2 Class Periods
This blended learning activity is highly recommended to help kids form deep understanding of the forces that act on a spring with mass attached. It combines a lab with a PhET simulation. Students identify the research question, make predictions, conduct a fair test, then compare their lab results to the simulation. With the sim, they can explore kinetic/potential energy transformation and "transport" their springs to different planets with varied gravitational constants. (Contains content support, student guides, & assessment/answer key.)
Level: Grades 5-8
Duration: Two Class Periods
A lesson for exploring the physics & engineering of artificial heart valves. Students examine and operate both a ball valve and a gate valve, then they work as a team of "engineers" to develop and sketch enhancements to the mechanical heart valve. Great activity for integrating engineering design in the secondary classroom.
Level: Grades 8-12
Duration: Two Class Periods
Kids explore civil engineering and architecture as they design and build a small dome frame that can withstand a load of 120 grams on top without collapsing. Editor's Note: For a great 3-day unit that brings in concepts of compression and tension, blend this lesson with the "Teachers' Domain Forces Lab" and the PBS Building Big digital resources in Activities directly below.
Level: Grades 5-9
Duration: 1-2 Class Periods
Activities:
This lab activity, developed by a Physics Teacher Resource Agent, gives directions for students to construct a very simple pendulum, then experiment with the mass of the bob and length of the string to see what factors affect the period of the pendulum. The printable student guide is easy to follow, yet challenges students to think deeply.
Level: Grades 7-10
Duration: One Class Period
Move objects of varying mass along a 1-D path and watch as the simulation displays graphs of position vs. time, velocity vs. time, and acceleration. Applied force, friction, and gravitational constants can be varied in this interactive activity. Can be adapted for use in either middle or high school.
Level: Grades 7-12
This activity is an animated introduction to simple machines. Designed for Grades 3-6, it helps children gain understanding of the different types of simple machine they encounter in their kitchens, garages, bedrooms, and bathrooms. Additionally the site provides a glossary of important terms, lesson plans and a teacher's guide.
Level: Grades 3-6
This is a collection of interactive animations that depict how forces and simple machines work together to create the compound machine. The authors designed it for Grades 3-6 to help children understand how compound machines function and how they are different from simple machines. It would be a good follow-up to the resource directly above -- Edheads: Simple Machines.
Level: Grades 3-6
This large collection of labs, activities, and interactive tutorials allows kids to explore large structures and what it takes to build them. They will investigate bridges, dams, tunnels, skyscrapers, and domes. The interactivity of the site is its hallmark feature, with simulation-based activities to explore forces, test the strength of materials, learn about structural load, and see how shape affects strength.
Level: Grades 4-12
References and Collections:
This resource directs teachers in the set-up of 20 engaging demonstrations relating to motion/mechanics. The materials include motion in one and two dimensions, coupled pendulum motion, rotational motion, and more. The author selected each demonstration for its "attention-getting" appeal and its ability to provoke thought about specific mechanical processes.
Level: Grades 6-12
Student Tutorials:
For the teacher planning a unit on amusement park physics, this tutorial can double as a student classroom activity. It offers an excellent overview of the forces acting upon a roller coaster as it travels on a straight, curved, or looped track. It includes a self-test at the end to gauge student comprehension. Free body diagrams and animations depicting kinetic/potential energy also enhance student understanding of a complex set of interactions.
Level: Grades 8-12
Duration: 20-30 minutes
The Universal Law of Gravitation (2)
Activities:
How did scientists first directly demonstrate that the Earth rotates? This short video, seen through the eyes of a child, explores the work of French scientist Leon Foucault -- a pendulum seems to rotate as it swings, but there is no external force that would cause the rotation (clockwise in the Northern Hemisphere, counterclockwise in the Southern). Through experiments, Foucault showed that it's not the pendulum doing the rotating. It's the steady, predictable movement of the Earth's rotation.
Level: Grades 3-6
Duration: 5 minutes
Content Support For Teachers:
This resource features well-organized text explanations alongside equations in a concept-building format for understanding gravitational interactions. Short problems and tables provide a concrete approach to helping learners grasp the universal nature of gravitational attraction so that formulas make sense.
Level: High School Physics
Frictional Forces (2)
Activities:
This simulation demonstrates motion of a block being pulled up an incline plane at constant velocity by a spring. By changing the angle of inclination, mass, and coefficient of friction, students can better understand how frictional force affects the movement of an object on a hill. Available in HTML5 or Java.
Level: Grades 8-12
This model, newly converted to HTML5, provides a highly visual way for students to investigate friction in a system of a skateboarder moving on a track. It begins with an idealized system (no friction) with bar graph showing changes in kinetic and potential energy as the skater moves along the track. Click "Friction" to set frictional force from low to high. As friction is introduced to the system, thermal energy is displayed alongside PE and KE in the bar graph. Students can readily see how friction affects the motion of the skater.
Level: 6-12
Duration: 30 minutes
Rotational Dynamics (1)
Activities:
Exactly what IS centripetal force and what does it do? This short video shot from NASA's International Space Station will help students understand the center-seeking force that results in circular motion. The environment is weightless, making it easy to watch the motion without the complicating effects of gravity.
Level: Grades 6-12
Duration: 5 minutes
Benchmarks and Standards (1)
References and Collections:
This resource is the Forces of Nature section of the Science Literacy Benchmarks published by the American Association for the Advancement of Science (AAAS). It is a statement of desired learning outcomes on the topic of physical forces and interactions for grades 2, 5, 8, and 12.
