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Natures Forces Simple Machines ELEMENTARY SCIENCE PROGRAM MATH, SCIENCE & TECHNOLOGY EDUCATION A Collection of Learning Experiences NATURES FORCES SIMPLE MACHINES Nature’s Forces Simple Machines Student Activity Book Name__________________________________________________________ This learning experience activity book is yours to keep. Please put your name on it now. This activity book should contain your observations of and results from your experiments. When performing experiments, ask your teacher for any additional materials you may need. TABLE OF CONTENTS Activity Sheet for L.E. #1 - Measuring Mass ...........................................................2-3 Activity Sheet for L.E. #2 - Measuring Weight.........................................................4 Activity Sheet for L.E. #3 - Measuring Force...........................................................5-8 Activity Sheet for L.E. #4 - Force, Weight and Mass...............................................9-11 Activity Sheet for L.E. #5 - Gravity – Gravity Everywhere .......................................12-17 Activity Sheet for L.E. #6 - Unseen Forces .............................................................18-23 Activity Sheet for L.E. #7 - Inclined Plane ...............................................................24-31 Activity Sheet for L.E. #8 - Wedge ..........................................................................32-33 Activity Sheet for L.E #9 - Screw.............................................................................34-35 Activity Sheet for L.E. #10 - Levers.........................................................................36-41 Activity Sheet for L.E. #11 - Pulleys........................................................................42-44 Activity Sheet for L.E. #12 - Wheel and Axle ..........................................................45-46 Natures Forces Simple Machines Student Assessment .........................................47-49 Student Self Assessment........................................................................................50 Glossary..................................................................................................................51-53 1 Activity Sheet for Learning Experience #1 Name______________________ MEASURING MASS Mass is a measure of the amount of matter in an object. Mass is defined by physical content, by the number of electrons, protons, molecules, etc. The basic measurement unit for mass is the gram or kilogram. Weight is a measure of the gravitational pull or attractive force of one mass to another mass (generally the Earth). A single ingot of gold would have the same mass wherever it was transported, but the weight of the ingot would be different on Earth than on the Moon or on Mars. The measurement of mass is not affected by gravity. An astronaut may be nearly weightless in space due to low gravity in space but if he were mass-less he would not be there. Calibrate your double pan balance. Mold clay into four ball shapes. Measure the mass of each ball shape with gram centimeter cubes. Add or remove clay to fashion two 25 gram and two 50 gram massed balls. A small amount of talcum powder may be used to reduce stickiness of each clay ball and aid rounding. Compare the masses of the balls by placing them in the double pan balance. Save the clay balls from this learning experience for use in later learning experiences. 2 Activity Sheet for Learning Experience #1 Page 2 1. What does calibrate mean when referring to the double pan balance?______ ________________________________________________________________ 2. Place a 50 gram ball in each basket of the double pan balance. How did your two 50 gram masses compare when you placed one in the basket of each double pan balance?____________________________________________ ________________________________________________________________ 3. Why do you think the double pan balance acted the way it did when you placed a 50 gram mass in each basket?_____________________________ ________________________________________________________________ 4. Place a 25 gram ball in each basket of the double pan balance. How did your two 25 gram masses compare when you placed one in the basket of each double pan balance?____________________________________________ ________________________________________________________________ 5. Why do you think the double pan balance acted the way it did when you placed a 25 gram mass in each basket?______________________________ ________________________________________________________________ 6. Place two 25 gram balls in one basket and a 50 gram ball in the other basket. How did your two 25 gram masses compare when you placed both in basket of the double pan balance and one 50 gram mass in the other?___________ ________________________________________________________________ 7. Why do you think the balance acted the way it did when you placed two 25 gram masses in one basket of the double pan balance and one 50 gram mass in the other pan? __________________________________________ ________________________________________________________________ 8. The amount of matter is measured in what metric unit? __________________ 3 Activity Sheet for Learning Experience #2 Name______________________ MEASURING WEIGHT Weight is a measure of the gravitational pull or attractive force of one mass to another mass (generally the Earth). A single ingot of gold would have the same mass wherever it was transported, but the weight of the ingot would be different on Earth than on the Moon or on Mars. For a definition of mass, see activity sheet for Learning Experience #1 in the Natures Forces Simple Machines Student Activity Book. In this learning experience you will use the Newton scale on a spring scale to measure force in Newtons. Find the weight (force) in Newtons on the following objects. Assemble the parts necessary for each measurement. Quantity Object to be measured Weight in Newtons 1 200 gram jar 2 200 gram jar 1 Friction box 1 Double sheave pulley 1 Friction box and double sheave pulley 1 Friction box, double sheave pulley, and friction block 1 Friction block The measure of the gravitational pull on an object is called ________________. The metric unit used to measure weight is called ________________________. 4 Activity Sheet for Learning Experience #3 Name______________________ MEASURING FORCE A force is a push or pull that changes the motion or shape of an object. A force must be used any time an object begins moving, changes direction, speeds up, slows down, or stops moving. An object that is not being subjected to a force will continue to move at a constant speed and in a straight line. An object that is at rest will remain at rest. This is called inertia. Changes in speed or direction of motion are caused by forces. The greater the force, the greater the change in motion. Think about hitting a ball with a bat. Given the same force, the more massive an object is, the less change in motion will occur. A light ball will go farther than a heavy ball when hit with a bat using the same force. Whenever an object exerts a force on another object, an equal amount of force is exerted back on it. Hitting a light ball with a bat does not hurt your wrists as much as hitting a massive ball. When an object speeds up, slows down, or changes direction, we know that an unbalanced force acted upon it. Force is often called “effort” in reference to simple machines. The international metric unit of force is the Newton (N). The Newton (N) was named after the English scientist Sir Isaac Newton. Force is commonly measured in pounds in the United States. 1. Place a single 200 gram mass on your desk or table. Pull the 200 gram mass with the spring scale. Record the force necessary to move the 200 gram mass at a steady rate across the surface of the table. Record the force in Newtons on the chart on page 7. 2. Place two 200 gram masses on your desk or table. Pull both 200 gram masses with the spring scale. Record the force necessary to move the 400 gram mass at a steady rate across the surface of the table. Record the force in Newtons on the chart on page 7. 5 Activity Sheet for Learning Experience #3 Page 2 3. Assemble the friction box, friction block, and the double sheave pulley with masonite side down on your desk or table. Pull the assembly with the spring scale. Record the force necessary to move the assembly at a steady rate across the surface of the table. Record the force in Newtons on the chart on page 7. 4. Assemble the friction box, friction block, and the double sheave pulley with abrasive side down on your desk or table. Pull the assembly with the spring scale. Record the force necessary to move the assembly at a steady rate across the surface of the table. Record the force in Newtons on the chart on page 7. 5. Assemble the friction box, friction block, and the double sheave pulley with double sheave pulley side down on your desk or table. Pull the assembly with the spring scale. Record the force necessary to move the assembly at a steady rate across the surface of the table. Record the force in Newtons on the chart on page 7. 6 Activity Sheet for Learning Experience #3 Page 3 6. Assemble the friction box, 200 gram mass jar, and the double sheave pulley with double sheave pulley side down to form wheel on your desk or table. Pull the assembly with the spring scale. Record the force necessary to move the assembly at a steady rate across the surface of the table. Record the force in Newtons on the chart on page 7. 7. Assemble the friction box, two 200
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