Fast and Furious Forces

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Georgia Performance Standards Framework for Physical Science – GRADE 8

Georgia Department of Education

Kathy Cox, State Superintendent of Schools

Physical Science GRADE 8 Fast and Furious Forces

July 2008 Page 1 of 11

Copyright 2007 © All Rights Reserved

Unit One Organizer: Fast and Furious Forces

(Approximate Time: 7.5 weeks)

OVERVIEW:

By eighth grade, we can assume that our students have gained an experiential understanding of motion. For example, they should

have learned that the harder they throw something, the faster it will travel, and that a large moving object (like a train) is harder to

stop than a small moving object (like a ball). While our students may be familiar with the observable effects of objects in motion,

they probably have not considered the causes which are responsible for altering their movement. Through a series of hands-on

activities, they can begin to comprehend that changes in motion always involve forces which push or pull on objects in a variety of

ways. They can learn how to generate the force needed to push a balloon car down the hall and they can measure, record, and

discuss how the amount of forces applied to various objects can affect how fast and how far and how they travel.

Eighth grade is a good time to for students to be introduced to the concepts derived by Isaac Newton, one of the greatest scientists of

all time. Newton was the first scientist to propose the idea of gravity and he discovered three important laws about motion. He also

was an expert in mathematics and even invented a kind of mathematics called calculus. According to legend, it was after he saw an

apple fall in the orchard (and maybe hit him in the head) that he realized that the same forces that determined the motion of the

moon were also acting on the apple. With his Universal Law of Gravity, Newton showed us that any two objects in the universe

exert gravitational attraction on each other. The degree of this attraction depends on the size (mass) of the objects and the distance

between them. Since the earth is by far the biggest object around us, it will exert the most pull on the other things around it (but the

other things will also pull back on the earth just a little). Perhaps more than any other scientist, Newton helped us to see how our

world works.

To conclude this investigation of force and motion, simple machines are introduced as tools that help us do work. Simple machines

make work easier for us by changing the force or distance needed to do certain kinds of work. Although students will have used

simple machines on a daily basis, they are often unaware of what they are or how they function. Most simple machines are designed

to let us exert less force than would normally be needed by moving further. All six types of simple machines, the lever, pulley,

inclined plane, wheel and axle, wedge, and screw help make work easier for us.








STANDARDS ADDRESSED IN THIS UNIT

Focus Standard:

S8P3. Students will investigate relationship between force, mass, and the motion of objects. a. Determine the relationship between velocity and acceleration.

b. Demonstrate the effect of balanced and unbalanced forces on an object in terms of gravity, inertia, and friction.

c. Demonstrate the effect of simple machines (lever, inclined plane, pulley, wedge, screw, and wheel and axle) on work.

S8P5. Students will recognize characteristics of gravity, electricity, and magnetism as major kinds of forces acting in nature. a. Recognize that every object exerts gravitational force on every other object and that the force exerted depends on how

much mass the objects have and how far apart they are.

Supporting Standards:

S8P2. Students will be familiar with the forms and transformations of energy. a. Explain energy transformation in terms of the Law of Conservation of Energy.

b. Explain the relationship between potential and kinetic energy.

c. Compare and contrast the different forms of energy (heat, light, electricity, mechanical motion, sound) and their

characteristics.

Habits of the Mind

S8CS2. Students will have the computation and estimation skills necessary for analyzing data and following scientific

explanations. a. Add, subtract, multiply, and divide whole numbers mentally, on paper, and with a calculator.

b. Use fractions and decimals, and translate between decimals and commonly encountered fractions – halves, thirds, fourths,

fifths, tenths, and hundredths (but not sixths, sevenths, and so on) – in scientific calculations.

c. Judge whether measurements and computations of quantities, such as length, area, volume, weight, or time, are

reasonable answers to scientific problems by comparing them to typical values.








S8CS3. Students will use tools and instruments for observing, measuring, and manipulating objects in scientific activities. a. Choose appropriate common materials for making simple mechanical constructions and repairing things.

b. Measure and mix dry and liquid materials in prescribed amounts, exercising reasonable safety.

c. Use computers, cameras and recording devices for capturing information.

d. Identify and practice accepted safety procedures in manipulating science materials and equipment.

S8CS4. Students will use ideas of system, model, change, and scale in exploring scientific and technological matters. a. Observe and describe how parts influence one another in things with many parts.

b. Use geometric figures, number sequences, graphs, diagrams, sketches, number lines, maps, and stories to represent

corresponding features of objects, events, and processes in the real world. Identify ways in which the representations do

not match their original counterparts.

c. Identify patterns of change in things—such as steady, repetitive, or irregular change—using records, tables, or graphs of

measurements where appropriate.

d. Identify the biggest and the smallest possible values of something.

S8CS5. Students will communicate scientific ideas and activities clearly.

a. Write instructions that others can follow in carrying out a scientific procedure.

b. Make sketches to aid in explaining scientific procedures or ideas.

c. Use numerical data in describing and comparing objects and events.

d. Locate scientific information in reference books, back issues of newspapers and magazines, CD-ROMs, and computer

databases.

S8CS6. Students will question scientific claims and arguments effectively. a. Support statements with facts found in books, articles, and databases, and identify the sources used.

b. Identify when comparisons might not be fair because some conditions are different.








The Nature of Science

S8CS7. Students will be familiar with the character of scientific knowledge and how it is achieved. Students will recognize that:

a. Similar scientific investigations seldom produce exactly the same results, which may differ due to unexpected differences

in whatever is being investigated, unrecognized differences in the methods or circumstances of the investigation, or

observational uncertainties.

b. Some scientific knowledge is very old and yet is still applicable today.

S5CS8. Students will understand important features of the process of scientific inquiry.

Students will apply the following to inquiry learning practices:

a. Scientific investigations may take many different forms, including observing what things are like or what is happening

somewhere, collecting specimens for analysis, and doing experiments.

b. Clear and active communication is an essential part of doing science. It enables scientists to inform others about their

work, expose their ideas to criticism by other scientists, and stay informed about scientific discoveries around the world.

c. Scientists use technology to increase their power to observe things and to measure and compare things accurately.

d. Science involves many different kinds of work and engages men and women of all ages and backgrounds.

ENDURING UNDERSTANDINGS

Forces are the pushes or pulls in nature produced by interactions between objects. Forces can cause objects to start moving, stop

moving, or change direction.

Objects tend to keep on doing whatever they’re doing (Law of Inertia). An object at rest stays at rest and an object in motion stays in

motion unless something else exerts a force on it.

An object’s size (mass) and the amount of force exerted on it affect its speed and direction. When forces on an object are balanced, the

object will either be at rest or move at a constant velocity. When forces on an object are unbalanced, the object will change its velocity.








Acceleration occurs whenever there is a change in motion of an object. Acceleration can involve a change speed and/or direction and

accelerations are caused by net forces. There are mathematical relationships between speed, velocity, acceleration, and time that can be

used to help understand motion.

Gravity refers to the force of attraction between any two objects in the universe that have a mass. The strength of this force of gravity

depends on the mass of the objects and the distance between them. Since the earth is an object with a very large mass, things on or near

the earth are pulled toward it by the earth's gravity.

Energy is the ability to do work. Without energy, forces can’t be generated to make things move or change.

ESSENTIAL QUESTIONS:

How are forces in nature related to the motion of objects?

How can forces be used to make objects move, change direction, or stop?

What are the similarities and differences between speed, velocity and acceleration?

What is friction and in what ways is it useful and in what ways is it problematic (e.g. in NASCAR races)?

How does gravity affect things on the earth?

How do simple machines make work easier for people?








Concept Know/Do Language Evidence

Forces in nature cause objects

to start moving, stop moving, or

change direction.

Define forces

Balanced forces

Direction

Force

Inertia

Position

Science Journals

Notebook check

Speed is a measure of how fast

something is moving. The

average speed is measured by

finding the distance traveled by

the object divided by the time it

takes to travel that distance.

Calculate speed. Distance

Time

Speed

Lab report (Speedy Straw

Racers)

NASCAR Balloon Car Cup

The velocity of an object

describes both the speed of an

object and the direction that the

object is traveling.

Differentiate speed and

velocity.

Distance

Time

Speed

Velocity

Lab report (Speedy Straw

Racers)


Acceleration occurs whenever

there is a change in motion of

an object. Acceleration can

involve a change speed and/or

direction and accelerations are

caused by net forces.

Calculate speed and velocity.

Graph measurement.

Differentiate between speed,

velocity and acceleration.

Distance

Time

Speed

Velocity

Acceleration

Lab report

(Speedy Straw Racers)


Friction is the force between

two objects when they rub

together. Friction makes

motion more difficult.

Diagram how friction acts to

slow the motion of a car on a

track. Explain how friction

makes motion more difficult.

Friction

Energy

Lab report

(Fact or Friction)

Science Journals









Gravity refers to the force of

attraction between any two

objects in the universe that have

a mass. The strength of this

force of gravity depends on the

mass of the objects and the

distance between them.

Define gravity and explain how

it relates to mass of the objects

and the distance between them.

Gravity

Force

Science Journals

Notebook Check

Simple machines are tools that

help us do work. Simple

machines make work easier for

us by changing the amount of

force needed to do certain kinds

of work.

Identify different types of

simple machines. Diagram how

each of them acts to make work

easier.

Inclined Plane

Lever

Pulley

Screw

Wedge

Wheel and Axle

Lab report

(Life is Easy with Simple

Machines)

Science Journals


Energy provides (is) the ability

to do work. Without energy,

forces can’t be generated to

make things move or change.

Describe how energy is used to

do work. Explain the

similarities and differences of

kinetic and potential energy.

Energy

Kinetic Energy

Potential Energy

Work


LANGUAGE:

Acceleration

Balanced forces

Direction

Distance

Energy

Friction

Force

Gravity

Inertia

Inclined Plane

Law of Conservation of Energy

Lever

Mass

Motion

Position

Pulley

Screw

Simple machines

Speed

Time

Velocity

Wedge

Wheel and axle

Work








MISCONCEPTIONS PROPER CONCEPTIONS

The only ―natural motion‖ is for an object to be at rest and, if an object is

at rest, there are no forces acting on the object.

Forces are pushes or pulls on objects that are needed to make an object

change its motion. An object at rest will remain at rest unless a force

acts on it and an object in motion will remain in motion unless a force

acts on it.

Velocity and speed are the same. Speed describes the rate of motion of an object. Velocity

describes both the speed and the direction of an object.

It is natural for things to fall down toward the earth and there is no need

to consider gravity as a concept to help explain why objects in the air fall

to the earth.

Gravity is the earth’s pull on things. Things on or near the earth are

pulled toward it by the earth's gravity. Gravity is always present.

Gravity only acts on things when they are falling. The force of gravity is the result of the attraction of the Earth on the

objects around it. Therefore, the force of gravity is always present.

Since friction is a force that hinders motion, you always want to reduce or

eliminate it.

Friction is often useful and beneficial. For example, the tread of a tire

is designed to maximize friction (traction) between the tire and the road

and friction can be used to produce heat when needed.

If an object is accelerating, it always means that it is speeding up. Any object that is changing speeds or direction is accelerating. An

object that is slowing down has a negative acceleration which is

commonly referred to as deceleration.

Heavier objects fall faster than light ones. All objects fall at the same rate of acceleration independent of its mass

if there are not frictional forces acting upon them. The acceleration of a falling object depends upon its mass.

All objects eventually stop moving when the force is removed. An object will continue to move with the same velocity forever if no

force acts on it.

Simple machines do work for us. Simple machines are tools that help us do work but they do not do it for

us. Simple machines make work easier for us changing the amount of

force needed to do certain kinds of work (i.e., provide a mechanical

advantage).

To ―work‖ means to exert oneself by doing mental or physical activity for

a purpose

While there are multiple definitions of the word work, the term in

science means to exert a force on an object in order to move it.








EVIDENCE OF LEARNING:

Culminating Activity: See end of framework document.

GRASPS

GOAL: Your challenge is to design a balloon car that will travel the furthest in the NASCAR Balloon Car Cup. To do this, you must

combine key concepts and understandings developed in this unit with your team’s creativity, common sense and ingenuity. Your task

as a team is to design and build a car that will maximize useful forces and minimize harmful friction to propel your car the longest

distance possible.

ROLE: You are a member of a Balloon Car Racing Team. Your team members include the driver, the crew chief, an engineer, and a

sponsor. Each person on the team has important roles to play. It is up to you as a team to determine each of your particular jobs and

responsibilities.

AUDIENCE: The car owner, the NASCAR board of directors, and racing fans everywhere.

SCENARIO: Normally, the winner of a race is determined by which car goes the fastest. But with fuel shortages increasing and gas

prices skyrocketing people are becoming more concerned with how cars can be designed to run more efficiently. Therefore, this year’s

Balloon Car Cup will focus on how far a car can go given a certain amount of fuel (push from the balloon). Your challenge is to design

a car that can minimize friction and drag to effectively push the balloon as far as possible.

PRODUCT: The design of your car must take into account key concepts of motion including forces, speed, friction, aerodynamics, and

simple machines. As part of the design process you must produce initial sketches of your car, a final detailed drawing, a written

explanation describing how your design incorporates each of the key concepts of motion, and the completed prototype car that you will

use on in the Balloon Car Contest. A design rubric is included for each group to guide their work and efforts.








UNIT RESOURCES

Velocity and Acceleration

http://www.schools.utah.gov/curr/science/sciber00/8th/forces/sciber/velaccel.htm

http://www.fearofphysics.com/Xva/xva.html

Balloon Cars

http://www.balloonhq.com/balloon_car/balloon_car.html

http://www.mrg-online.com/car.htm

Friction

http://www.school-for-champions.com/science/friction.htm

Gravity

http://www.sciencenetlinks.com/Esheet.cfm?DocID=111

http://sunshine.chpc.utah.edu/javalabs/java12/machine/index.htm

http://www.schools.utah.gov/curr/science/sciber00/8th/forces/sciber/velaccel.htm

http://www.fearofphysics.com/Xva/xva.html

http://www.balloonhq.com/balloon_car/balloon_car.html

http://www.mrg-online.com/car.htm

http://www.school-for-champions.com/science/friction.htm

http://www.sciencenetlinks.com/Esheet.cfm?DocID=111

http://sunshine.chpc.utah.edu/javalabs/java12/machine/index.htm








The Balloon Car Cup – Culminating Activity Rubric Exceeds Expectations

4 points Meets Expectations

3 points Does Not Meet Expectations

2 points

Evidence of Scientific Understanding: Explanation

The student clearly explains how and in what manner forces act on the balloon car to propel the car forward.

The student attempts to explain how and in what manner forces act on the balloon car to propel the car forward.

The student did not explain how and in what manner forces act on the balloon car to propel the car forward.

Evidence of Scientific Understanding: Force and Mass

Student car design shows a clear understanding of how the amount of force acting on the car and the mass of the car will affect the speed of the car and the distance that it travels.

Student car design shows some understanding of how the amount of force acting on the car and the mass of the car will affect the speed of the car and the distance that it travels.

Student car design shows little understanding of how the amount of force acting on the car and the mass of the car will affect the speed of the car and the distance that it travels.

Evidence of Scientific Understanding: Frictional Effects

Student design shows and explains that car has been built to minimize friction (especially between the wheels and the track) and drag.

Student design shows that car has been built to minimize friction – especially between the wheels and the track and drag.

Student design fails to show that car has been built to minimize friction – especially between the wheels and the track and drag.

Organization and Analysis Student recording, organization and analysis of the race results are thorough, detailed and aligned with the key concepts of this unit.

Student recording, organization and analysis of the race results are adequate and aligned with the key concepts of this unit.

Student recording, organization and analysis of the race are minimal and inadequate and not aligned with the key concepts of this unit.

Effort and Participation Student actively participated and worked hard in each aspect of this exploration and interacted with team members in a positive and encouraging manner.

Student participated and worked in each aspect of this exploration and interacted with team members in a positive and encouraging manner.

Student did not participate or work in each aspect of this exploration and failed to interact with team members in a positive and encouraging manner.

Documents

Fast and Furious Forces