Physics – Conservation of Energy – The Chain Reaction Recycling Machine Work Stations Pinning It! Ramp Race Student Experience Students rotate around the stations writing observations and explanations of how each station relates to work and what they think the components of work are. Students try to drive a into a wooden block by dropping a ping-pong ball and a golf ball on the pin. Students identify the factors that go into potential energy. Students construct two ramps; both start from the same height and end rolling flat on the ground or table. Students “race” marbles down the ramps and figure out how to determine the velocity of the marbles at the bottoms of ramps. Students compare final velocities and try to interpret why they are relatively the same. T4T Material Teacher’s choice: block of wood, string, cart, ramp, weight, pulley, heavy object For each group: 1 golf ball, 1 ping-pong ball, 1 push pin, 1 wooden block. For each group: 4 blinds, two 4-inch tubes, two 10-inch tubes. Big Idea If work is to be done, a force is needed. If an object is forced to move, it takes more work to move it further. W = F∆x PE = mgh ∆PE = W It takes work to lift an object. Once it is lifted it has potential energy. That potential energy can be used to do work. Marbles may take different amounts of time to reach the bottom but their final velocities are relatively the same. Conservation of Energy ∆PE = ∆KE Connection to Culminating Activity Work is a central concept for the culminating activity. By placing objects in strategic positions, they can store potential energy for later use. Mechanical energy is conserved CA Standards IE1. d PH2. b and c; IE1. d, j PH2. c; IE1. b, c, j Next Gen Sci Standards HS-PS3-1 Asking questions and defining problems. Constructing explanations and designing solutions. HS-PS3-2 Asking questions and defining problems. Constructing explanations and designing solutions. HS-PS3-2 Asking questions and defining problems. Analyzing and interpreting data. Constructing explanations and designing solutions. pin
Time One 55 min period One 55 min period Two 55 min periods lessons are not intended to be a complete unit, but, rather a learning activity guide for concept attainment. Teachers should supplement these lessons with appropriate reading material and problem sets. Energy of Motion Simple Machines and Concepts The Reaction Recycling Machine Student Experience Students use one of the ramps from Ramp Race to investigate the connection between height of the ramp and velocity of the ball at the bottom of the ramp. Students collect data and investigate the relationship between PE and KE for the ball on the ramp and the equation for the KE. KE = ½ mv2 Students rotate through stations and play/look at simple machines and other concepts. They describe what they do. They try to imagine how each could help to connect their ramp to someone else’s ramp. They draw a sketch of how they plan to connect their ramp to someone else’s ramp. Students connect all other ramps to make a whole-class chain reaction machine. The last ramp places a plastic bottle in the plastic recycling bin and a wad of paper in the paper recycling bin. Students determine potential energy, kinetic energy, work done by friction on their ramp, work done to start the next ramp. T4T Material One ramp from “Ramp Race” and height adjusters (books, other tubes, etc.) Simple Machines Stations The Cart Big Idea KE = ½ mv2 Simple machines get work done. They can be used to make connections in the chain reaction (Rube Goldberg) machine. Energy can transfer from one form to another. Work done by friction can be calculated by using the ideas of conservation of energy. Connection to Culminating Activity Mechanical energy is conserved. KE can be determined by measuring mass and velocity. Simple machines are inspirations for connecting the ------ CA Standards PH2. a none PH2. a, b, c Next Gen Sci Standards HS-PS3-1 Asking questions and defining problems. Analyzing and interpreting data. Constructing explanations and designing solutions. Asking questions and defining problems. Constructing explanations and designing solutions. HS-PS3-3 Asking questions and defining problems. Analyzing and interpreting data. Constructing explanations and designing solutions.