Classroom activities help students understand that heat energy can be produced by mechanical and electrical machines.
Dorling Kindersley Eyewitness Books: Electricity by Steve Parker Dorling Kindersley Eyewitness Books: Energy by Steve Parker
Heat energy can be produced by mechanical and electrical machines. Light can also sometimes be produced. Mechanical machines are those which do not use electricity, such as machines that use fuel (cars, lawn mowers), human strength (bikes, skateboards), or flowing water (water turbine). Classroom examples of mechanical machines include using scissors, a stapler, or a pencil sharpener. To use these machines, a student would provide the energy. So to measure the temperature difference, a student could measure the temperature of his/her hand before using the machine, a measure the temperature of the hand after using the machine for a minute or two.
Electrical machines include those which use electrical power and would have a plug or use batteries. Classroom examples include an overhead projector, electric pencil sharpener, computer, heat lamp, TV, or VCR.
1. Use a Science Process and Thinking Skills
4. Communicate Effectively Using Science Language and Reasoning
Pre-Assessment/Invitation to Learn
Review with students how mechanical and electrical machines can produce heat. Have students identify as many machines as possible in the classroom. Ask them how scientists would measure how much heat is produced. Scientists use measurements, so they would measure the temperature of the machines before it is turned on, and after it has been turned on for a while.
Homework & Family Connections
Students may measure temperatures of machines at home.
|Grading student worksheet:|
|10 points||correct, complete, detailed|
|8 points||partially correct, complete, detailed|
|6 points||partially correct, partially complete, lacks some detail|
|5-1 points||incorrect or incomplete, missing data, needs help|