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Motion: force, gravity, acceleration, inertia, friction, & energy

Motion unit activity & plans

Questioning is the basis of all learning.

Overview

Introduction

A sequence of plans to facilitate a review and develop a deeper understanding of movement and the variables that affect it.

  • Movement is affected by many factors including gravity, acceleration, inertia and surface friction.
  • Acceleration is the change in speed of an object. Inertia is the tendency of objects to stay in motion or to stay still. In order to start something moving or to stop it from moving, a force must be applied to overcome the inertia.
  • A force can be a push, pull or throw.
  • Gravity is a force that applies the same force on objects no mater the weight of the object.
  • Surface friction can slow an object's acceleration and momentum (inertia). Variables that effect friction include texture, weight, and shape.

Background information:

This plan is designed for students who have very little prior knowledge of motion. However, they probably should have some conservation skills, such as believing variables that affect motion will do so consistently, or is conserved (always be).

Related study topics:

Big ideas, concepts, facts, and outcomes

Big ideas

  • Objects can be explored to make claims about their motion and the variables that affect how it changes, is constant, and how to measure it. Equilibrium is a state where the net forces is zero.

Related concepts and facts

  • Better decisions (claims) are made when information is verified, with evidence and reasoning, before being considered accurate and used to reason and develop explanations and models to understand the world and make decisions.
  • People make better decision when they understand and consider the positive and negative influences that effect their decision making.

Outcome

Use accurate verifiable information to consider and decide how objects can be balanced or made more stable.

Science concepts: physical, earth, life

Big ideas: The motion of objects and their interactions with other objects can be predicted fairly accurately.

Related concepts

  • Everything on or anywhere near the earth is pulled toward the Earth's center by gravitational force. Every object exerts gravitational force on every other object. The force depends on how much mass the objects have and on how far apart they are. The force is hard to detect unless at least one of the objects has a lot of mass.
  •  In the absence of forces, an object at rest will stay at rest.
  • In the absence of forces, such as friction, an object will stay in motion in the direction of of its motion and with its speed.
  • Whenever an object increases or decreases its speed or changes direction, a force is acting on it.
  • The greater the force, the greater the change in motion.
  • The more massive an object, the less effect a given force will have.
  • Inertia is a property of objects (matter) where they tend to stay the same or not change. If at rest, stay at rest, if in motion, stay in motion in a straight line, unless an external force causes a change.

Outcome

  1. Predict and explain the motion of objects, their interactions, and the possible results.

Science inquiry, process, & perspective concepts, facts, & outcomes

Big ideas: Science (claim evidence & reasoning) can be used to understand and explain cause and effect in the world.

Related concepts and facts

  • Variables describe properties that change and can be used to explain interactions.
  • Relative position describes changes in positions of objects when they are moved relative to a common position.
  • Systems are used to describe objects that interact together.
  • Interactions can be explained by describing how variables change within a system and how a system interacts with other objects or systems.
    • Objects change.
    • Change can be observed and recorded as before, during, after.
    • Change is observed through properties of the object.
    • Change can vary.
    • Constancy Somethings stay the same and some things change.
    • Constancy can sometimes be observed during a very slow rate of a change process or focusing on a particular property.
  • When I experiment I collect observations that describe how different properties change (become variables) when objects and systems interact. This helps me make claims, explain what is happening, and to predict what might happen in the future.
  • Inquiry concepts
  • Process concepts
  • Perspective concepts

Outcome

  1. Ask questions, identify variables to explore, and create and implement plans that explore them to find answers to different questions.

Pedagogical Overview

Activities Sequence to provide sufficient opportunities for students to achieve the targeted outcomes.

Make sure students have the prior knowledge identified in the background information.

  1. Activity 1 - What is inertia?
  2. Activity 2 - Do heavy objects fall faster than light objects?
  3. Activity 3 - How does gravity effect acceleration?
  4. Activity 4 - Paper Airplanes
  5. Activity 5 - Ball on carpet/linoleum
  6. Activity 6 - Objects on ramp
  7. Activity 7 - Box and rubber band

Focus question

Unit focus question:

What is motion and what variables affect it? How do things move, what causes their motion, and how do we explain motion?

Sub focus questions:

  1. How do objects move?
  2. What causes them to move?
  3. What cause them not to move?
  4. What is Inertia?
  5. Do heavy objects fall faster than light objects?
  6. How does gravity effect objects?
  7. How does gravity effect acceleration?
  8. How does mass, acceleration, and inertia affect paper airplanes?
  9. What is the difference of a ball rolling on a carpet or linoleum?
  10. How do objects roll on a ramp?
  11. What is friction and how strong is it?

Materials

  • Glass, card (4x4), coin, balls, spheres, or other objects with different weights to drop, sheets of paper, ramp, ball or sphere, tape measure, clock with seconds, several types of paper, tape measure,

Lab notes

References and other resources

Notes on graphing and fact sheet for learners

Scoring guides suggestions (rubric)

Rotational motion (scoring guide)

Top level

  • Describe motion of objects with consideration of inertia, force, and friction.
    • Describe force as a push or pull.
    • Inertia Objects at rest will stay at rest until acted upon by an outside force. Objects in motion will stay in motionwith the same speed and the same direction (in a straight line) unless acted upon by a force.
    • Describe a greater force creates increased speed or a longer distance an object travels before stopping.
    • Describe the amount of mass in an object as a variable that effects motion by the transfer of energy or the force applied.
    • Describe the velocity of an object as a variable that effects the transfer of energy or the force applied.
  • Accurately describe inertia, force, and friction individually when focused on each. Don't combine them in expanation of motion.
  • Describe motion as what happens when an object is pushed or pulled.
  • Describe motion as movement that can be easy or hard to depending on the object. Doesn't describe variables that affect motion.

Lower level

Lesson Plans

Activity 1 - Inertia

Materials

Focus questions:

  • How do objects move?
  • What causes them to move?
  • What cause them not to move?
  • What is Inertia? A property of objects (matter) where they tend to stay the same or not change. If at rest, stay at rest, if in motion, stay in motion in a straight line, unless an external force causes a change.

Learning outcomes:

  1. Define inertia.
  2. Explain the inertia of different objects at rest and in motion.

Suggested procedures overview:

  1. Put learners in groups, focus their attention, and assess their initial understanding of the focus questions.
  2. Demonstrate card and coin drop.
  3. Explain objects at rest stay at rest unless acted on by an outside force.

Exploration -

  1. Put learners in pairs.
  2. Ask and accept all answers without comment for accuracy.
    • How do things move? up, down, forward, backward, circular? curvy?
    • What causes them to move? Push, pull, force
    • What cause them not to move? friction, gravity, mass, glue, inertia
  3. What would happens when riding in a car and the driver applies the breaks? They feel like they are being pushed forward.
  4. Tell. Lets model something similar to riding in a car.
  5. Demonstrate set up:
  6. Place a card on a glass with a coin in the middle of card.
  7. Ask. What forces are acting on the coin? gravity, friction, maybe the card pushing
  8. Ask. What would happen if the cardboard were suddenly taken away? coin will or will not move
  9. Have the learners create their own set ups to explore what happens when they give the card a quick flip. The penny will fall to the bottom of the cup.
  10. Assist learners so they are successful.

Invention -

  1. Assemble as a whole group.
  2. Ask. How were you able to get the coin to drop into the glass? The coin will stay put if the card doesn't push the coin sideways, then it will dropped down into the glass, because gravity is pushing or pulling it toward the center of the Earth.
  3. Ask. Have you heard of inertia?
  4. What is it? A property of objects (matter) where they tend to stay the same or not change. If at rest, stay at rest, if in motion, stay in motion in a straight line, unless an external force causes a change.
  5. Ask. How does inertia have an affect on the coin?
  6. What force causes it to drop into the glass? gravity
  7. What force does the bottom of the glass have on the coin. Pushes up on it so it stops and rests on the bottom of the glass.
  8. What happens to the coin if no other force than gravity is applied to the coin?
  9. Ask. How does inertia act on a bike and rider?
  10. A person on ice skates?
  11. Discuss inertia and gravity effects on different objects.

Discover

Challenge learners to put the hex nut into a pop bottle.

Explain how it might be done.

Inertia hoop to bottle drop

 

 

Activity 2 - Falling objects

Materials:

Focus questions:

  1. Do heavy objects fall faster than light objects?

Learning outcomes:

  1. Observe objects of different weights fall at the same time.
  2. Explain how gravity acts on all objects proportionally the same.

Suggested procedures overview:

  1. Put students in groups, focus their attention, and assess their initial understanding of the focus questions.
  2. Activity twirl zoomers.
  3. Describe

Exploration

  1. Put students in pairs.
  2. Ball up a piece of paper.
  3. Hold the ball of paper in one hand and a ball in the other.
  4. Say. Predict which object will fall faster.
  5. Drop both objects at the same time. both objects should land at the same time.
  6. Repeat experiment with a variety of objects.
  7. When satisfied all agree they saw several objects of different weight (mass) fall at the same rate, then ...
  8. Drop a balled up piece of paper and a sheet of paper. The ball of paper should land first.

Invention

  1. Ask. What causes the un-balled piece of paper to take longer to fall. Air acts as a force or friction that slows it down.
  2. What objects do people use to slow the effects of gravity? parachute
  3. How does it work?
  4. Review. Weight (mass) doesn't affect how fast objects fall based on the force of gravity. Friction can.

Discover

Activity 3 - Gravity and acceleration

Materials:

  • Ramp, ball or marble, tape measure, and clock
  • Lab note 3

Focus questions:

  1. How does gravity effect acceleration?

Learning outcomes:

  • Describe how objects increase their speed when they fall or roll down an ramp (incline).

Suggested procedures overview:

  1. Put students in groups focus their attention, and assess their initial understanding of the focus questions.
  2. Activity

Exploration

  1. Put learners in pairs.
  2. Make a ramp long enough for a sphere to roll down it for three or more seconds.
  3. Start the sphere at the top and mark where the sphere is at the end of 1 second, 2 seconds, and 3 seconds.
  4. Measure the distances and graph the results.

Invention

  1. Discuss what the results and create an explanation for acceleration and gravity.

Discovery

  1. Ask. If a person jumps our of an airplane, high enough, will he continually accelerate until she hits the ground? An object in a vacuum near sea level will accelerate at approximately 9.8 m/s2, no matter what its weight (mass). With air resistance acting on an object that has been dropped, the object will eventually reach a terminal velocity, which is around 53 m/s (190 km/h or 118 mph) for a human skydiver increase it's speed or accelerate all the way to the ground.

 

Activity 4 - Paper airplanes

Materials

  • Several types of paper, and tape measure
  • Lab note 4

Focus questions:

  1. How does mass, acceleration, and inertia affect paper airplanes?

Learning outcomes:

  1. Fly paper planes.
  2. Explain how, mass, acceleration, and inertia affect the flight of a paper airplane.

Suggested procedures overview:

  1. Put students ingroups, focus their attention, and assess their initial understanding of the focus questions.
  2. Activity

Exploration

  1. Ask. How do you make a paper airplane?
  2. What variables affect its flight? weight, size, shape, how launched
  3. What combination of variables will cause it to fly farther? optimal amounts of weight, size, shape, and how launched
  4. Ask. If we are to compare data we collect, what will should we change and keep the same?
  5. Decide on variables to keep the same (control) and change.
  6. To investigate mass, acceleration and inertia, the design should be controlled.
  7. Have learners design, make, and test fly their paper airplanes.
  8. Can have them use a variety of papers and designs so the design they choose will allow them to test different variables.
  9. To agree on a design have them test fly different designs and decide together on a design that will allow them to collect data for different variables the want to explore.
  10. Decide on what variables to test. planes weight (can add paper clip), wing surface area, launch style (angle, force), .
  11. Decide on a design and what variables to test and how to change them.
  12. For example first flight to test airplanes design
  13. Use distance of the plane's flight for the responding variable. Could graph planes surface area and distance. If do may want to share Notes on graphing and fact sheet for learners

Invention

  1. Have the class compare their plane’s features with the distance the planes flew.
  2. Suggest to explore adding weight to their designs and add a paperclip to the plane.
  3. Test the plane to see how far it will fly this time.
  4. Keep adding weight to the plane and see how far it will fly.
  5. Ask how much weight is too much weight to add to the airplane.
  6. Discuss how real planes are designed with this information in mind.

Discover

  1. Explore plane variables and flight. Aerodynamics

Activity 5 - Rolling spheres

Materials:

  • Marbles, tape measure, carpet, and linoleum floor.
  • Lab notes 5

Focus questions:

  1. What is the difference of a ball rolling on a carpet or linoleum? (friction or resistance)
  2. What is friction?
  3. How do we change friction in our world to achieve a purpose?

Learning outcomes:

  1. Roll spheres across different surfaces.
  2. Explain how different surfaces have different textures and different textures can result in different amounts of friction (friction coefficients).

Suggested procedures overview:

  1. Put students in groups, focus their attention, and assess their initial understanding of the focus questions.
  2. Activity

Exploration

  1. Organize learners into pairs and groups.
  2. Have students predict if an object will slide farther on a rough or smooth surface.
  3. Place a sphere (marble) on the carpet floor.
  4. Flick the marble.
  5. Measure how far the marble rolled.
  6. Repeat procedure on the linoleum or tile floor; remember to flick with the same force.

Invention

  1. Ask. What may have caused the marble to role farther on the smooth floor?
  2. Explain how this effect is friction.
  3. Ask. Where else the class may have experienced friction. sliding a couch on carpet, pulling a wagon on gravel

Discover

  1. Ask. How can the amount of friction be changed?
    • Make the surface smooth (polish it, use metal, glass or other smooth material).
    • Reduce the size of surface - ball bearings,
    • Add lubrication - oil in motors, gears, transmissions,
    • Add gravel or sand to ice to increase friction.
    • Treads on shoes.
  2. Select one example and research. Explain how friction is different depending on the method or methods used to change the amount of friction and how it achieves a purpose.

 

Activity 6 - Ramps

Materials

  • Tape, square of cardboard, toy car, eraser, coin, button, stone, and ruler.
  • Lab notes 6

Focus questions:

  1. How do objects slide on a ramp?

Learning outcomes:

  1. Describe

Exploration

  1. Organize learners into groups and pairs.
  2. Tape one end of the cardboard to a desk.
  3. Pick one of the objects, feel the surface of the object and the ramp, and predict how high the free end of the cardboard will need to be lifted so the object selected can slide down the board.
  4. Place the object on the free side of the cardboard.
  5. Hold the ruler perpendicular to the desk.
  6. Lift the cardboard till the object starts to slide down the cardboard.
  7. Record the height the cardboard was lifted before the object began to slide.
  8. Repeat experiment with all objects and order them by the height of the ramp or angle of slope.
  9. If all groups used the same set of objects, then have them chart their ranking so everyone can see them.

Invention

  1. Discuss the data.
  2. Ask. What properties did the sliders have in common and what properties did the non sliders have in common?
  3. Ask. Why did the cardboard have to be lifted higher for some of the objects? Some objects had more surface friction.

Discover

  • Ask. Do you think we can measure the surface friction? yes, no. Which surface?
  • Say. We will measure the surface friction in the next activity.

Activity 7 - Friction

Materials

  • Two pieces of string, rubber band, small cardboard box, tape, ruler, objects of different mass, smooth surface (desktop), and rough surface (carpet floor)
  • Lab notes -

Focus questions:

  1. What is friction?
  2. How strong is it?

Learning outcomes:

  1. Describe friction as resistance to a sliding object.
  2. Describe the amount of stretch of a rubber band is a measure of force.
  3. Describe the additional distance a rubber band is stretch when sliding an object across a surface from when the same object is hanging in air would represent the force of friction between the sliding object and the surface on which it is slide.

Exploration

  1. Organize learners into groups and pairs.
  2. Tie one end of a piece of string to the rubber band. Tie another piece of string on the other end of the rubber band. Tape one of the pieces of string to the side of the box securely.
  3. Have learners predict how long the rubber band will have to stretch before the box begins to move.
  4. Place box on smooth surface.
  5. Pull the unattached end of the other string; use the ruler to measure the length of the stretched rubber band just as the object begins to move.
  6. Record the length of the stretched rubber band.
  7. Place some objects in the box and repeat steps 3 & 4.
  8. Repeat experiment with a variety of weight in the box and record data in lab notes.
  9. Have groups record some of their data so all can view it during the coming discussion.

Invention

  1. Ask. What did you discover? The more weight in the box the more the rubber band is stretched. The same objects on the smoother surface stretched the rubber band less than on the carpet (rough surface).
  2. Ask. How did the force change with more weight in the box. The force needed to be stronger when weight was added.
  3. Ask. Have you had experiences when more force was needed when weight was increased? Riding a bike with two people, pulling a wagon full of rocks.
  4. Have you had experiences when more force was needed when moving an object from one surface to another. dragging something from wood floor to carpet. sidewalk to muddy or grassy area.

Discover

The seven activity plans are modified from activity plans by Ginger Hingst & Rick Steffenhagen

Lab Notes for activities

Lab notes 1 - Inertia

Materials

  • Container, small object, card

Challenge

Use an objects inertia to make it drop mostly straight down.

 

Procedure

Describe what you do.

 

 

 

Describe how one object's motion can and can not affect another objects motion.

 

 

 

Describe two forces you used, or controlled, to make an object (coin or hex nut) drop straight down.

 

Lab notes 2 - Falling objects

Materials

  • two objects of different weights or mass

Challenge

Drop each object at the same time and observe how long each drops relative to the other.

Procedure

Describe what you do.

 

 

 

What relationship did you discover between the weight (mass) of objects with different masses.

 

Lab notes 3 - Gravity and acceleration

Materials

  • Ramp, spheres,

 

Describe what you do and what happens.

 

ten x ten grid

 


Lab notes 4 - Paper airplanes

Materials

 

Focus questions:

  • What affects the flight of paper airplanes?

 

Challenge

Select a variable that affects the flight of a paper airplane and collect data to show how changing the variable affects the flight.

Data

 

ten x ten grid

 

 

Relationship of variable on flight

 

 

Lab notes 5 - Rolling spheres

Materials

Challenge

Describe what friction is and how it is different on two different surfaces.

 

 

 

 

Select one example of the use of friction and research. Explain how friction is different depending on the method or methods used to change the amount of friction and how it achieves a purpose.

Example

 

 

 

 

Friction in the system is between

 

 

 

 

 

Friction is changed by

Lab notes 6 - Ramps

Materials

  • Ramp and objects to test for sliding

Challenge

Determine what variables of different objects makes them slide or not slide.

 

Procedure

Test four objects to see when they will slide when a ramp is raised, record the height or angle for each object, a description of the objects surface texture, and kind of material the object is made.

Object 1 2 3 4
Name        
Description




        
Texture




        
Material




        
Slide order        

 

Summary What properties did the sliders have in common and what properties did the non sliders have in common?

Lab notes 7 - Friction

Materials

  • Two pieces of string, rubber band, small cardboard box, tape, ruler, objects of different mass, smooth surface (desktop), and rough surface (carpet floor)

Challenge

How does the forces change when sliding or dragging objects of different weights (mass) across different surfaces.

 

Procedure

 

Data

  Objects in box Objects in box Objects in box
Force needed to suspend box & load in mid air.
In cm rubber band stretches		      

 

Force needed to slide box & load
In cm rubber band stretches 		Objects in box Objects in box Objects in box
On smoother surface      
On carpet




      
On other surface



      

 

Relationships

 

 

Material Sheets

B

 

 

 

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