# 2.2.2.2 Forces

2
Subject:
Science
Strand:
Physical Science
Substrand:
Motion
Standard 2.2.2.2

The motion of an object can be changed by push or pull forces.

Benchmark: 2.2.2.2.1 Forces Making Objects Move

Describe how push and pull forces can make objects move.

For example: Push and pull objects on smooth and rough surfaces.

Benchmark: 2.2.2.2.2 Falling Objects & Force

Describe how things near Earth fall to the ground unless something holds them up.

## Overview

Standard in Lay Terms

MN Standard in Lay Terms

By causing an object to move, students see the direct connection between what they do and how the object changes.  Pushing and pulling an object will change how it moves.  The reason things near the earth fall to the ground unless something holds them up is called gravity.

Big Ideas and Essential Understandings

Big Idea

A force is a push or a pull.  Force gives an object the energy to move, stop moving, or change direction.  When you write with a pen you exert a force.  When you peddle your bike, blow your nose, turn on a faucet, chew your gum, or swim in a pool, you are exerting forces on other objects.  We would never be able to move without exerting forces on things.

If something is dropped, why does it fall?  GRAVITY is the reason, of course, but why?  What is it about gravity that causes things to drop to the ground?  Earth's gravity doesn't make things fall down - it makes things fall towards the middle of the planet.  That goes for everything on Earth - its skies, its oceans and its people.

Benchmark Cluster

MN Standard Benchmarks

2.2.2.2.1  Describe how push and pull forces can make objects move.  For example: Push and pull objects on smooth and rough surfaces.

2.2.2.2.2  Describe how things near Earth fall to the ground unless something holds them up.

The Essentials

NOTE: The concept of gravity, and that all objects pull on all other objects is a concept that will be better explored in later grades. Research also states that students may not realize the magnitude of the Earth's gravitational force.

Video clips:

2.2.2.2.1 Pushes and Pulls

Studying forces and motion helps children understand the world around them and explore how things interact with each other.  This movie explores forces, or pushes and pulls, which can change the way something moves.  It also introduces position and how motion is a change of position.

2.2.2.2.2 Gravity and Falling Objects

Students investigate the force of gravity and how all objects, regardless of their mass, fall to the ground at the same rate.

 Gravity Friday, September 26, 2003 If gravity were turned around We'd all fall up instead of down. If I fell up I'd laugh out loud To bump my head into a cloud. There'd be no skinned elbows or knees, Picking up clothes or raking leaves. And planes would need more sky to share For cars would soar into the air. I probably would never cry If I slipped and fell up in the sky. But how would we stay on the ground If gravity was turned around?

Pull the string, and it will follow wherever you wish.

Push it, and it will go nowhere at all.

Dwight D Eisenhower.

Correlations

NSES Standards:

##### Content Standard B

As a result of the activities in grades K-4, all students should develop an understanding of:

• Properties of objects and materials.
• Position and motion of objects.
• Light, heat, electricity, and magnetism.

See this site

AAAS Atlas:

The way to change how something is moving is to give it a push or a pull. 4F/P2 (ID: SMS-BMK-0213)

Benchmarks of Science Literacy:

Things move in many different ways, such as straight, zigzag, 'round and 'round, back and forth, and fast and slow. 4F/P1

The way to change how something is moving is to give it a push or a pull. 4F/P2

See this site.

Common Core Standards

The K-2 student...learns best by building understanding from their own actions upon objects and by telling stories about what they did and what they found out.

As they impose their ideas on the world, trying things out to see what will happen (poking, pushing, feeling, etc...), children see the results of their actions and thus come to understand how part of their world works.  If these experiences are connected with language experiences (e.g. talking with students as they explore instead of having a summary discussion after an exploration), primary students will learn how to express what they have learned in clear and accurate terms.

See this site.

ELA

Writing:

2.6.7.7

Participate in shared research and writing projects (e.g., read a number of books on a single topic to produce a report; record science observations).

## Misconceptions

Student Misconceptions
• An object a person is sitting or standing on doesn't push back with equal force.  The person is just resting on it.
• A force is put on a projectile when it is launched and the force gradually decreases causing the object to slow and eventually stop when the force is used up.  (A thrown rock, hit ball, bullet.)
• The faster an object is moving the greater the force on it.
• Objects move in the direction of the strongest force.
• Gravity is an invisible force pulling us all down towards the center of the Earth and keeps us from falling off the Earth as it spins at thousands of miles an hour, and people in Australia are upside down!

See this site.

## Vignette

On Monday, Mrs. N. asked her students to brainstorm everything that they knew about the word "force."  She recorded their answers on a chart.

She then said "Force is a push or a pull and many forces are acting on you all of the time. Usually you don't even realize that the force of gravity is acting on you, but it is, all of the time.  If you are falling, it's pretty obvious that something is pulling you down but even if you are standing on the floor, perfectly still, the force of gravity is still pulling you down.  And the really hard thing to understand is, if you are standing perfectly still on the floor, the floor is pushing up on you just as hard as gravity is pulling you down!"

"Let's see if we can understand this by doing some simple experiments with rubber bands."  She then handed out one rubber band to each student.  "I want you to slowly stretch a rubber band and think about what you are doing.  Most people use two hands placed at opposite ends of the rubber band and pull with each hand away from each other.  This means there are two pulling forces acting on the rubber band in opposite directions."

"Now try to stretch the rubber band by using one hand and by grabbing the rubber band at only one place.  We know it's possible to stretch the rubber band with one hand using your thumb and finger at two different places, but can you figure out a way to stretch the rubber band by applying the force at only one place?  If you hooked the rubber band over something to stretch it, is there only one force acting at only one place?  Try it and see."

"Next, I want you and your partner to stretch a rubber band by pulling on either end.  Did you notice how one person can stretch a rubber band by pulling at either end?  When you hook a rubber band over something like the leg of a chair, does the chair pull when you pull the other way on the rubber band?  Think hard about this, one of the smartest people who ever lived finally figured this out and before he did, no one understood it."

The next day, Mrs. N. reviewed with the class what they had learned about pulling.  "You must pull to stretch a rubber band but forces are just as often exerted by pushing.  Today you will experiment to see what happens when you push something."

She then gave everyone a paper binder clip.  "Using your thumb and index finger, push inward on the 'ears' of the binder clip until it opens.  Now open it by using the thumbs on each of your two hands.  Notice, every time you open the clip, you must push in the opposite direction in two different places.  Now try to open the clip by holding only one of the 'ears.'  If you did this by pushing with one hand while the other 'ear' was pressed against a table or a wall, are you really pushing on the clip in only one place?"

"Let's see what happens when you work with your partner.  Two people who are able to cooperate can open the clip by pushing together on each of the two 'ears.'"  (Careful experimentation should reveal that each of the two people must push equally hard in the opposite direction.  However, you should find that it is impossible to open the clip using a single force on only one of the "ears".)

Mrs. N. then said "I want you to think hard about this.  Most people think that walls and tables can't push but what is the difference between having a friend pushing on one side of the clip or having a wall push on one side of the clip?  If you understand this, you will finally understand that whenever you push on something, it will always push back with an equal force."

Modified from Applying Forces, Doing Work and developing Power

## Resources

Instructional Notes

Suggested Labs and Activities

NOTE: Whether one is 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 (pushing and pulling) that affect motion.

2.2.2.2.1 Pushes and Pulls

In groups, students will learn to identify pushes and pulls. Students will learn how a push or pull will affect various items.

This lesson plan was created as a result of the Girls Engaged in Math and Science University, GEMS-U Project.

2.2.2.2.1 Motion and Forces in Your World

A resource designed to increase educators' understanding and teaching of physical science.  Participants explore physical science concepts of motion, force, and matter that are part of daily life and learn how to incorporate observation, discourse, and experimentation to increase understanding of physical science by students at the elementary level.

2.2.2.2.1 Push or Pull?

This book, and the lesson plans that go with it, demonstrate the physical forces of pushing and pulling.

2.2.2.2.1 Forces and Motion

This page contains worksheets, online activities, and other educational resources to help children learn the concepts involved with forces and motion.

Students will learn about different forces that can be used to move things and the language to use when talking about force.

2.2.2.2.1 Motion

Students will design an efficient model of playground equipment that shows an understanding of push, pull, and friction and their effect on movement.

2.2.2.2.1 Sort it Out - Push or Pull?

Students investigate the difference between a push and a pull.  In this science/physics lesson, students observe and discuss pictures from a book.  Additionally, students are placed into groups to make observations of pictures and to sort them as a push or pull.  Groups compare and contrast their sorts with the other groups.  Students discuss that science is all around them.

2.2.2.2.2 Why Gravity Causes things to fall

If something is dropped, why does it fall?  GRAVITY is the reason, of course, but why?  What is it about gravity that causes things to drop to the ground?

2.2.2.2.2 Gravity - May the Force be With You

Students will complete several activities to learn about gravity.

2.2.2.2.2 Understanding Gravity

A science lesson on understanding gravity.  This lesson focuses on what gravity is, Isaac Newton, the laws of gravity, force, motion, and inertia.  Includes printable teaching reading comprehension lesson worksheets.

2.2.2.2.2 Gravity At Work

An excellent resource that includes: Vocabulary, Games, E-Review. ·

2.2.2.2.2 Build a Roller Coaster

Very simple lesson in gravity, balance, and motion.  A Foss website.  Not difficult, and fun.  Grade 2+

Instructional Resources

Instructional suggestions/options

2.2.2.2.1 On The Move

"On The Move" brings readers into the viewing stands of an ice rink to learn about force and basic laws of motion. They'll discover that when skaters are gliding, spinning, going forward, backward - or even stopping - force is at work.

2.2.2.2.1 Pushing and Pulling

In this lesson, students identify motion as a push or a pull. Students will:

• Describe motion as a push or a pull.
• Identify the motion of an object as a push or a pull.
• Trace and measure the motion of an object.

2.2.2.2.1 Newton and Me, by Lynne Mayer

A little boy and his dog, Newton, discover much about forces of motion in this story as the two spend the day together exploring. Through simple, everyday child-friendly activities, such as rolling a ball, pushing a toy truck, pulling a wagon, riding a bike, and playing tug-of-war, children will learn a great deal about motion and moving objects.

5 E Lesson on Force

 Engage Day 1: Students will begin a KWL concerning motion. They will answer the question: What do they already know about how objects move (predictions)?
 Explore Students will journal their predictions and share. Students will be given a partner and asked to explore how their objects move and journal their data.
 Explain Students will review findings from the day before. Teacher will then lead students in a discussion of what the students have "learned" about how objects move Technology Resources: Students will watch Bill Nye the Science Guy, Motion and respond in their journals.
 Extend Students will add to the KWL chart with their findings from the week. Technology Resource
 Evaluate Evaluate: Whole Group Discussion Charts, Student Science Journals, Student Directed Lab Results, and Individual Performance Task for Motion.

See this site.

2.2.2.2.1 Let's Get Moving with Force

Students will observe objects as they move, and they will express their ideas on the type of motion, such as stopping, starting, falling, straight, zigzag, circular, and the vibrations that the object is undergoing.

Students will identify the forces of push and pull on a moving object and predict the direction it will go.

2.2.2.2.2 Why Gravity Causes things to fall

If something is dropped, why does it fall?  GRAVITY is the reason, of course, but why?  What is it about gravity that causes things to drop to the ground?

2.2.2.2.2 Gravity - May the Force be With You

Students will complete several activities to learn about gravity.

2.2.2.2.2 Understanding Gravity

A science lesson on understanding gravity.  This lesson focuses on what gravity is, Isaac Newton, the laws of gravity, force, motion, and inertia.  Includes printable teaching reading comprehension lesson worksheets.

2.2.2.2.2 Gravity At Work

An excellent resource that includes: Vocabulary, Games, E-Review. ·

2.2.2.2.2 Build a Roller Coaster

Very simple lesson in gravity, balance, and motion.  A Foss website.  Not difficult, and fun.  Grade 2+

2.2.2.2.2 Falling

This lesson introduces students to gravity as a force, focusing on the concept of falling.

New Vocabulary

Vocabulary/Glossary

Force: strength or energy exerted; cause of motion or change.  Context: Both teams know that getting their vehicle up the hill will require a great deal of force.

Gravity: the force by which all objects in the universe are attracted to each other.  Context: The glass fell off the table and gravity made it hit the floor instead of floating up.

Motion: a change in position of an object.  Context: The ball stayed in motion as it rolled down the ramp.

Pull: to exert force on (someone or something), typically by taking hold of them, to move or try to move them toward oneself or the origin of the force.  Context: He pulled the car door handle.

Push: an act of exerting force on someone or something to move them away from oneself.  Context: He closed the door with a push.

Technology Connections

2.2.2.2.1 Push or Pull?

Demonstrate a change in the motion of an object by giving the object a push or a pull.

2.2.2.2.1 What is force?

A force is a push or a pull.  Force gives an object the energy to move, stop moving, or change direction.  This online resource is interactive and allows students to answer questions and see force applied.

2.2.2.2.1 Elementary School: Forces and Motions Intro.

In this video, students explore the concepts of force and motion by interacting in group activities such as a tug-of-war game.  Goals for this lesson include understanding the cause and effect relationship between force and motion, what these words mean, and how these concepts are relevant in the outside world and can be applied to daily life.

2.2.2.2.1 Push, pull, play the game!

When you push something, you can move it away from you.  When you pull something, you can move it toward you.

2.2.2.2.1 Force

Have you ever played tug of war?  In this game, two teams pull the ends of a rope in opposite directions.  The team that pulls the other team across the center line wins.  When a team pulls the rope, they apply force.  Want to know more about force?  Let's explore and find out.

Interactive Games

2.2.2.2.1 Pushing and Pulling

Changing Shape - Push, Pull, Stretch · Forces & Movement · The Particle Adventure - The Fundamentals of Matter and Force.

Promethean/Smartboard Activities

2.2.2.2.2 Force and Motion

Explains gravity, sound, simple machines, magnets and other area of force and motion.

2.2.2.2.1Get Me Moving Question set (SMART Response question set)

Use the Senteo interactive response system to learn about push and pull.

Read, brainstorm, drag objects, erase to reveal answers, and move weights on a balance scale to learn about forces, mass, gravity, weight.

2.2.2.2.1 On the Move (Smartboard lesson)

Simple introduction of motion, force, push and pull.

Through doing the activities in this pack, pupils should:

• Know the difference between pushing and pulling.
• Understand the effects of pushing and pulling on stationary objects.
• Be able to predict what will happen when a toy car is pushed.
• Be able to draw conclusions from an investigation.
• Relate what they have learned to everyday occurrences.

2.2.2.2.2 Gravity on Earth and in Space

Most of us spend our entire lives held close to Earth's surface by the force of gravity. This collection of images compares the experience of gravity on Earth with that of the astronauts' perceived weightlessness in space.

2.2.2.2.2  Presentations in PowerPoint format

For Kids

For Teachers

2.2.2.2.2 ESPN Sports Science homepage

The Emmy Award-winning TV series, hosted by John Brenkus, uncovers sports' biggest myths and mysteries by using cutting-edge technology to measure momentum, friction and the laws of gravity. (This is advanced but your kids will think it's really cool!)

Learn about gravity and the force that keeps the Earth's moon in orbit.

References

Applying Forces, Doing Work and Developing Power.

An activity lesson with handouts with student activities to experience the differences.

## Assessment

Assessment of Students

Question the students about the difference between a push and a pull.

Online quiz: student read the action and decide if it's a push or a pull.

There are several activity masters that students can complete that show if/how items are pushed or pulled.

Students are given a variety of toys that work by pulling or pushing. They create a Venn diagram and place the toys in the correct places. See this site.

Description:

In this video, the instructor uses formative assessment to gauge his students' understanding of force and motion.  Together as a class, the students draw conclusions and make claims based on evidence from their experiment which illustrated these concepts.  The instructor leads this discussion and asks questions to keep the students engaged and focused:

• Do heavier or lighter objects require more force to overcome gravity and be lifted up?  What causes this?  (Answer: Heavier.  Weight is the measure of that force.)
• Look around the school, playground, and your home.  What objects do you see hanging down (swings, tetherball, mobiles, clothes on hangers, etc.)?  What could be some problems or how could your life be different if gravity did not pull all of these objects straight down?

Assessment of Teachers

1. The movement of objects is caused by what?  What else affects the movement of objects?

(The movement is caused by the basic actions of pushing or pulling.  How an object moves by one of these forces depends on a number of factors: size, weight, shape and the degree of friction.)

2. Describe the force of friction and the force of gravity in each situation below:

• You slip on a wet floor and fall down. (The water on the floor makes it slippery. There is less friction on the feet and that makes it easy for a person walking on it to fall over. The force of gravity pulls the falling person to the ground).
• You push a heavy box down a ramp. (Here the force of friction makes it harder to push the box. But the force of gravity pulling the box down the ramp helps.)
• You climb up a slide with just your socks on your feet. (The force of gravity pulls against the climb making it harder to climb up. Your socks slip on the surface of the sliding board giving you less friction to grip with.)

3. What must act upon an object in order for it to move?

(A force must act upon an object in order for motion to occur.  When more force is applied, more movement will be observed. When less force is applied to the same object, less movement will be observed.  Pushes and pulls are forces that make movement occur.)

4. What is the difference between pushing and pulling?

(Push means that the object is moving away from the person pushing, and pull means the object is moving towards the person pulling.)

5. Describe what gravity is.

(Gravity is a force of nature that works between two bodies of matter in the universe to try and pull them together.  The best example possible to explain gravity is to look at a person.  You are a body of matter.  The earth is also a body of matter.  Gravity pulls you down to the earth and allows you to walk around instead of floating.)

## Differentiation

Struggling Learners

Struggling and At-Risk

Students who do not fully understand forces of motion can explore this BBC website.  This website can be embedded in a class website to encourage home-to-school connections.

English Language Learners

ESL students will be introduced to the unit.  New vocabulary will be introduced such as names and adjectives to describe properties.  At different stages during the unit, ESL students will be introduced to some of the scientific terms used in this unit in the context of discussions and hands-on activities.  They will receive support with their experiments write-ups (writing will be scaffolded by using sentence starters).

A good collection of worksheets, exercises, lesson-plans, online games, etc.

An online resource that contains Translated Concept Summaries in Spanish, Chinese, Hmong, Khmer, and Vietnamese.

This chart lists step-by-step directions for how to link core science standards for ELL students. See Force and Motion, Position, Gravity, Force.

Extending the Learning
• Have students visit the playground and look for opportunities to see how the forces of pushing and pulling move the playground equipment.
• This site allows students to explore the force of a roller coaster.  Students are able to build their own coaster and then given a safety and a fun rating on their design.
• Give students time to explore this site on their own and then they can demonstrate to the class their findings as the class explores the site together.
• Have students investigate Aristotle, DaVinci, and/or Newton and the important contributions they made to our understanding of gravity.  There are engaging, readable books, as well as excellent websites, for student exploration.  Prepare a presentation for the class (e.g., posters, brochures, PowerPoints, play, etc.).
• On the How Things Fly exhibit, students can do the activity called Free Fall, in which they use the results of three different experiments to solve an online mystery.  See this site.
• Gravity and Weight on Other Planets
• Students will practice multiplication skill and learn about mass, weight, and gravity.
Multi-Cultural

This chart lists step-by-step directions for how to link core science standards for ELL students.  See Force and Motion, Position, Gravity, Force.

Developing Cultural Sensitivity in Science Class:

How can traditional methods of teaching science be improved through multicultural, social reconstructionist education?  Here are a few tips to help teachers get started.

Special Education
• Give learners more time to complete all work.
• Assign teaching assistant to help with any reading or writing activities.
• Assign peer buddies to help with the activities.

Classroom Observation

An administrator observing a lesson might see students pushing and pulling various items (blocks, toy cars, Unifix cubes, etc.). The teacher would be circulating around the room and asking students to demonstrate push and pull - requiring that the students use the words to describe how they made their item move. In addition, students will be doing gravity experiments such as: Does gravity makes heavier things fall faster than lighter ones? Predict and examine the direction seeds will grow and thereby learn about the effects gravity has on seeds and plants.

Parents

Pushes and Pulls Family Activities

Studying forces and motion helps children understand the world around them and explore how things interact with each other.  This movie explores forces, or pushes and pulls, which can change the way something moves.  It also introduces position and how motion is a change of position.

Push & Pull Science Activities

Force - how objects move - is an important scientific phenomenon that children should understanding.  Teach children about force with activities and lessons that center on pushing and pulling.

Gravity for Kids

What keeps us from floating off into space?  Why does something I drop fall to the ground?  Kids are famous for asking questions like these, which usually cause parents to mumble something about gravity or tell them they will learn it when they get older.  Here are a number of resources that can answer some of those questions.

Gravity Science Lessons for Kids

You would be floating away from earth right now if it wasn't for gravity.  Gravity is important for many other reasons, too, as some simple science lessons for kids can clearly demonstrate.  It's an invisible force, but a strong one.  Use experiments to help your kids explore it and reveal how it is interwoven with life on earth.

Read more: Gravity Science Lessons for Kids | eHow.com

Gravity