Exploring Science Concepts
Unit: Physical Science
Strand E Forces and Motion
Grade Two
November 2010
FOSS Instructional Pedagogies
Inquiry
Hands-On Active Learning
Multisensory Learning
Student-to-Student Interaction
Discourse and Reflective Thinking
Reading- FOSS Science Stories
FOSS Web
Balance and Motion Overview
Three Investigations- each with subset of activities
Designed for students to:
Investigate materials constructively during free exploration and in a guided
discovery mode.
Solve problems through trial and error & develop persistence in tackling a
problem.
Explore concepts of balance, counterweight, and stability.
Observe systems that are unstable and modify them to reach equilibrium.
Discover ways to produce rotational motion & construct and observe toys that
spin.
Explore and describe some of the variables that influence the spinning of objects.
 Observe
 Explore
and compare rolling systems with different-sized wheels.
and describe the motion of rolling spheres.
 Acquire the
vocabulary associated with balance and motion.
Investigation 1
Balance
Four Parts
Science Concepts:
• Objects can be balanced in
many ways.
• Counterweights can help
balance an object.
• A stable position is one that
is steady; the object is not
falling over.
• The way an object balances
can be changed by
counterweighting.
• The position of an object can
be described by relating its
locations to another object.
Purpose:
Students will…
• Discover numerous ways to balance
tagboard shapes.
• Find ways to balance a pencil on its
point, in stable positions.
• Explore the concepts of balance,
counterbalance, counterweight, and
stability by balancing tagboard
shapes, making mobiles, and
engaging in other balancing projects.
• Communicate observations and
comparisons of balanced objects,
using precise vocabulary.
Investigation 1 Balance
Part 1: Trick Crayfish
Focus:
• Objects can be balanced in
many ways.
• Counterweights can help
balance an object.
• The way an object balances
can be changed by
counterbalancing.
Task:
1. Introduce the crayfish
2. Balance on finger
3. Can crayfish be balanced in
other ways?
4. Introduce clothespins , allow
inquiry, suggest moving pins
in different locations. Get
crayfish to balance on its
noselike projection or
rostrum.
Investigation One: Balance
Part One Trick Crayfish
5. Call to rug and ask:
- What did you do to get the crayfish to balance on its
nose?
- Does it matter where you put the clothespins?
6. Introduce “counterweight”- use to balance in new ways
7. Challenge students to find new ways to balance their
crayfish.
8. Wrap Up:
- Discussion
- Word Bank
- Content Chart
Investigation 1
Balance
Part 2: Triangle and Arch
Focus:
• A stable position is one that
is steady; the object is not
falling over.
• The place on which an object
balances is called the balance
point.
• Counterweights should be
placed low on an object in
relation to the balance point.
Tasks:
1. Revisit balancing of crayfishintroduce as a stable position;
demonstrate what happens
with a gentle push
2. Introduce new shapeschallenge to balance shapes on
end of craft stick rather than
finger
3. Discover stable & unstable
positions using one/two
clothespins with each shape.
Investigation 1
Balance
Part 2: Triangle and Arch
4. Ask:
- Can you get it to balance
another way?
- How many ways can you make a
stable position using only one
clothespin for a counterweight?
- Can you balance both objects at
the same time?
- Try working with a partner,
together can you find new ways
to make stable balanced
systems?
5. Assess Progress :
- Use Stable Positions Sheet
If needed, redistribute materials
and allow students to set up the
systems shown in the pictures to
see if they are stable
6. Wrap Up:
- Word bank- stable, arch, triangle,
balance point
- Concept Chart- How can you tell
by looking at a picture if it is a
stable system?
-
Investigation 1
Balance
Part 3: The Pencil Trick
Tasks:
Focus:
1.
Review Part 2- recall stable systems
• Counterweights should be
and to think about where clothespins
placed low on an object in
were put.
relation to the balance point. 2. Challenge students to balance
• The position of an object can
tagboard pencil on craft stick using
clothespins; remind students to test
be described by relating its
stability.
location to another object.
3.
-
Call to rug- discuss balancing , ask:
Where did you put the clothespins to
get a stable system?
Can you get a stable system using no
clothespins? One? Two?
Where did you place the
counterweights to get a stable system?
Investigation 1
Balance
Part 3: The Pencil Trick
4.
5.
6.
Give the real pencil
challenge- balance a
sharpened pencil on its
point on the craft stick
Introduce the wire- wire
can be attached to the
pencil, but not used to tie
pencil to the craft stick
Assess Progress via teacher
observation; provide hint if
needed; allow students to
share successes.
7. Wrap Up:
- Discussion:
How might you balance a stick
on top of a 2-liter soda bottle?
How could you balance a chair
on a tight rope?
Word Bank
Content Chart: What is the trick
to balancing an object on one
point?
Read science story, Make It
Balance!
What we learned from
Investigation 1 Balance
Science Concepts:
• Objects can be balanced in many ways.
• Counterweights can help balance an object.
• A stable position is one that is steady; the object
is not falling over.
• The way an object balances can be changed by
counterweighting.
• The position of an object can be described by
relating its locations to another object.
Investigation 2 Spinners
Three Parts
Science Concepts:
1. Objects and systems that turn on a central axis exhibit
rotational motion.
2. The amount and position of mass affect how an object
rotates.
3. A push or pull (a force) is needed to initiate rotational
motion in objects and systems.
Investigation 2 Spinners
Part 1 Tops
Inquiry Question:
• How can spinning tops be changed?
Investigation Summary:
• Students make tops from plastic disks and shafts, and spin them.
After finding the arrangement of parts that produces the best top,
they make tops from other materials.
Science Content:
1. Objects and systems that turn on a central axis exhibit rotational
motion.
2. You need a force to start a top spinning.
3. The amount and position of mass affect how the object rotates.
Investigation 2
Spinners
Part 1: Tops How can spinning tops be changed?
Important Points to Lesson:
1. Do not tell students how to make tops- the challenge is how to
use the materials to make a good top.
2. Discuss Top Progress (#6) introduce “rotating”
3. Challenge students further:
•
Best design for a top that spins a long time?
•
Best design for a top that spins fast?
•
Does it make a difference if big or small disks are used?
4. Assess Progress (#10)
5. Wrap Up- word bank, concept chart
6. Science Stories Push or Pull?
Investigation 2 Spinners
Part 2 Zoomers
Inquiry Question:
• How can a spinning object be kept in motion?
Investigation Summary:
• Students use disks and a length of string to make zoomers.
Science Content:
1. There are different ways to initiate rotational motion.
2. The motion of an object can be changed by pushing or pulling.
3. Tops and zoomers both spin, but in different ways.
Investigation 2
Spinners
Part 2: Zoomers How can a spinning object be kept
in motion?
Important Points to Lesson:
1. Review type of motion tops make- indicate zoomers also rotate
(spin) when in motion.
2. Demonstrate the zoomer in action
3. Demonstrate knot tying
4. Some students will have difficulty getting zoomer assembled and
going; let them work at the problem for a while before assisting
5. Wrap Up- word bank, concept chart
6. Science Stories Tools and Machines & the story Move It, But
Don’t Touch it
Investigation 2 Spinners
Part 3 Twirlers
Inquiry Question:
• How can air start an object spinning?
Investigation Summary:
• Students make twirlers (flying spinners) that rotate by air
resistance, first modifying soda straws with wings, and then
making twirly birds from paper and paper clips..
Science Content:
1. Variations in design can influence the rotational motion of
spinning objects.
2. Air resistance can act as the force that initiates rotational
motion.
Investigation 2
Spinners
Part 3: Twirlers How can air start an object
spinning?
Important Points to Lesson:
1. At start review spinning motion of tops and zoomers. Point out
a force had to be applied to start the spinning motion.
2. Challenge students to get straw to spin- let them discover
3. Limit directions by you on how to assemble twirlers
4. Test twirlers
5. Use questioning (#8 #9) to assess progress
6. Wrap Up- word bank, concept chart
7. Science Story Things That Spin
Investigation 3 Rollers
Three Parts
Science Concepts:
1. Things move in many different ways.
2. Wheels and spheres roll down a slope.
3. Axles support wheels.
4. Wheel-and-axle systems with wheels of different sizes roll
toward the smaller wheel.
5. The amount and location of an added weight can change the
way a system rolls.
Investigation 3 Rollers
Part 1 Rolling Wheels
Inquiry Question:
• How can a wheel-and-axle system be changed?
Investigation Summary:
• Students set up cardboard ramps down which they roll plastic disks.
They put the disks on slim shafts to make wheel-and-axle systems.
They try all kinds of configurations of wheel size, axle length, and
axle position to get the rolling systems to perform a variety of tricks.
Science Content:
1. Wheels roll down a slope.
2. A slope is a surface that is higher on one end.
3. Axles support wheels.
4. Wheel-and-axle systems with wheels of different sizes roll toward
the smaller wheel.
Investigation 3
Rollers
Part 1: Rolling Wheels How can a wheel-and-axle
system be changed?
Important Points to Lesson:
1. At start identify rotating(spinning) as one kind of motion and
how it is identified.
2. Discuss early results using ramps and large wheels(#6) before
introducing axles
3. After making tricky rollers provide small wheels
4. Encourage sharing of results and collaboration
5. Show and Tell (#12) Discuss similarities in design- identify roll
fast, farthest, slowest
6. Wrap Up: word bank and concept chart
Investigation 3 Rollers
Part 2 Rolling Cups
Inquiry Question:
• Can we predict the behavior of a rolling cup?
• What happens if weight is added to a rolling-cup system?
Investigation Summary:
• Students roll paper cups down ramps. They observe the way cups roll and
use the predictable curved rolling path to meet challenges. They put cups
together to make them roll straight and weight them in various ways to see
how weight affects rolling.
Science Content:
1.
Cups roll in the direction of the smaller end.
2.
To roll straight, two cups can be taped together so the ends are the same
size.
3.
The amount and location of an added weight can change the way a
system rolls.
Investigation 3
Rollers
Part 2: Rolling Cups Can we predict the behavior of a rolling
cup? What happens if weight is added to a rolling-cup system?
Important Points to Lesson:
1. Review kind of motion wheels make-rolling
2. Maintain inquiry nature of cup rolling task.
3. Pose questions (#4) prior to “Park the Car Problem”
4. Try to go straight- let students try their ideas
5. Add weight (coins) to straight roller- discuss (#13)
6. Wrap Up: word bank, content chart
7. Science stories Rolling, Rolling, Rolling!
Investigation 3 Rollers
Part 3 Rolling Spheres
Inquiry Question:
• How can we make a runway system that will keep a marble rolling?
Investigation Summary:
• Students roll marbles in cups and down runways. They work with the
flexible runways to make the rolling marbles do tricks. As a
culminating experience, students work together as a class to connect
the runway sections to make one long runway through which a
marble can roll nonstop.
Science Content:
1. Spheres are round in all directions and roll in all directions.
2. A runway must be high at the start and low at the finish for a
sphere to roll the complete length.
3. Spheres roll down a slope.
Investigation 3
Rollers
Part 3: Rolling Spheres
How can we make a runway
system that will keep a marble rolling?
Important Points to Lesson:
1.
At start review rolling motion of wheels and cups; contrast with shape of
a sphere.
2.
Free exploration- challenge students to find out how marbles roll in the
runways.
3.
Marble tricks- care with foam runway
4.
Teams of students may work together to connect their runways.
Demonstrate how to connect two runways.
5.
Discuss key points before building LONG runway
6.
Keep it trial and error till success is met.
7.
Assess Progress with Marble Runways worksheet
8.
Wrap Up: word bank and concept chart
9.
Science stories Strings in Motion FOSS Web animation
Part 1: Trick Crayfish Wrap Up
Discussion Questions:
Where should you put clothespins on a paper crayfish to get it to
balance on its side?
How could you get the crayfish to balance straight up and own on
its tail?
Word Bank: crayfish, balance, clothespin, counterweight
Content Chart- lists statements that summarize knowledge acquired
from investigations
- How do you know when something is balanced?
- Think about all the different ways you balanced the crayfish. Is
there anything you noticed that is always the same?
Formative
Assessment
-Part of the
shape resting on
the stick is the
balance point.
- small black
rectangle is end
of craft stick