Exploring Machines

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Lou Loftin

FETC Conference

Orlando, FL

January 28 – 31, 2014

Workshop Agenda

• Looking at STEM

• Investigating and Experimenting with Machines

• The Science Behind the Machines

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Science and Technology

“The goal of science is to understand the natural world, and the goal of

technology is to make modifications in the world to meet human needs.”

(NRC, 2000)

• Throughout the science learning process, students experience

engineering, technology, and mathematics first hand as they model and

explore science concepts that technology has exploited over time to

better meet our human needs.

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NSES Science Content StandardsGrade 5-8Unifying Concepts and Processes

– Systems, order and organization

– Evidence, models & explanation

– Change and measurement

– Form and function

• Science as Inquiry

– Abilities necessary to do scientific inquiry

– Understanding about scientific inquiry

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NSES Science Content Standards (cont)

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•Physical Science

- Motions and Forces

- Transfer of Energy

•Science and Technology

- Abilities of technological design

- Understanding about science and technology

Next Generation Science Standards

• Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.

• Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object and the mass of the object.

• Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem

• Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.

ITEEA Standards

Students will develop an understanding of:

– The Characteristics and Scope of Technology• New products and systems can be developed to solve problems or

to help do things that could not be done without the help of technology.

– The Core Concepts of Technology • Systems thinking

– involves considering how every part related to others.– applies logic and creativity with appropriate compromises in

complex real-life problems. 7

NCTM Standards and Expectations• Algebra

• Instructional programs from pre-kindergarten through grade 12should enable all students to—

– Understand patterns, relations, and functions

– Represent and analyze mathematical situations and structures using algebraic symbols

– Use mathematical models to represent and understand quantitative relationships

– Analyze change in various contexts

• Understand patterns, relations, and functions

NCTM Standards and Expectations (cont)

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• Grades 6–8 Expectations: In grades 6–8 all students should–- represent, analyze, and generalize a variety of patterns with tables,

graphs, words, and, when possible, symbolic rules;- relate and compare different forms of representation for a relationship;

• Represent and analyze mathematical situations and structures using algebraic symbols• Grades 6–8 Expectations: In grades 6–8 all students should–

- develop an initial conceptual understanding of different uses of variables;- use symbolic algebra to represent situations and to solve problems,

especially those that involve linear relationships;- recognize and generate equivalent forms for simple algebraic expressions and solve linear equations

Common Core State Standards for Mathematics

• Mathematical Practices – -- Make sense of problems and persevere in solving them.-- Reason abstractly and quantitatively.

• Expressions and Equations–Apply and extend previous understandings of arithmetic to algebraic expressions.–Reason about and solve one-variable equations . . . .–Represent and analyze quantitative relationships between dependent and independent variables.

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Set Components

• 1432 K’NEX Pieces

• Build 30 different models (4 of each

model simultaneously)

• Supports 8 – 12 students working in

teams

• Teachers’ Guide on CD that includes

14 lessons.

Key Concepts

• Levers, pulleys, inclined planes,

wedge, screw, wheel and axle

• Gears

• Energy Transfer

• W=Fd (computation of work input

and work output)

• Effort and Resistance Forces

• Classes of levers

• Computing Mechanical Advantage

(Ideal and experimental)

• Technological Design Process

• Experimental Design

• Motion and Forces

• Science and Technology in Society

• Systems

Q: Why do we use simple machines?

• Our challenge as teachers is to help students understand what “make work

easier” means.

• We could do this by asking students to read and to memorize a textbook

explanation.

• Or we can help them learn rich content through probing questioning techniques

and the hands-on investigation of machines and models of real-world machines.

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A: Because simple machines make work easier.

Some Vocabulary

• Fulcrum• Effort• Load• Newton• Torque• Force

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Can you list the various simple machines?

• Levers• Pulleys• Wheels and Axles• Inclined Planes• Wedges• Screws

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Build One of the These Models• Hammer• Balance• Nutcracker• Screwdriver• Crank fan• Bottle Opener• Scissors• Rowboat• Axe • Eggbeater

• Take a piece of chart paper and make a single page poster for your model.

• Include:– Name of machine– The type of simple machine– A sketch of the model– List of ways that the machine makes work

easier.– List one or two ways you could alter the

machine to make work even easier.

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Present Your Findings

• Each group will briefly describe what they have discovered.• Use your model and your poster to guide your presentation.• Feel free to ask questions of your audience during the presentation.

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Activity Summary

• Time for exploration provided an opportunity to extend and apply

information we learned earlier.

• The poster focused exploration and added an interdisciplinary aspect to

the project.

• Group work stimulated discussion and analysis of the machines.

• The oral presentations strengthened communication skills and informed

others.

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Simple Machines and Work

• The word work in physical science is much different than the everyday use of the term. In science it is often referred to as mechanical work.

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• Work can be defined mathematically as W= Fd. – Work is equal to the force applied to an object times the distance

over which the force is applied.• Force is measured in Newtons• Distance is measured in meters• Work is measured in Joules

Simple Machines and Work (cont.)

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– Increase a force put into the machine

– Increase the distance over which a force is applied

– Change the direction of a force

– Reduce friction

• Simple machines can ‘make work easier’ in several ways:

Simple Machines and Work (cont.)

• A simple machine can make work easier in several ways but, it can never

produce more work output than the work that is put into the machine

(efficiency).

• Many simple machines are used to multiply the force that is applied to a

task. If the machine multiplies your force, it is easier to complete the task.

• Since there is no ‘free lunch’ in science, what do you have to give up to

enable the machine to multiply the force that is applied to the task?

• The answer is distance!

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Simple Machines and Work (cont.)• The relationship between the work put into a simple machine and the

work output of that machine can be summarized as:Work (Input) = Work (Output)

OrF (input) X d (input) = F (output) X d (output)

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• Changing one of the values in the formula has an impact on the other values. If you apply an input force to a simple machine for a greater distance for example, the output force will increase if the output distance remains the same.

Summary

• Simple machines make work easier.• Simple machines do mechanical work.• Simple machines can be analyzed using the formula for

mechanical work (W=Fd).• Work (input) = Work (output)• Efficiency of machines is less than 100%

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