http://www.teachengineering.org/view_lesson.php?url=collection/duk_/lessons/duk_hockey_music_less/duk_hockey_music_less.xmllessontext/xmlEngineering K-Ph.D. Program, conservation of energyfrictioninertiakinetic energyhockeyConservation of energyFrictionInertiaKinetic Energy

Students are introduced to the concept of inertia and its application to a world without the force of friction acting on moving objects. When an object is in motion, friction tends to be the force that acts on this object to slow it down and eventually come to a stop. By severely limiting friction through the use of the hover pucks, students learn that the energy of one moving puck is transferred directly to another puck at rest when they collide. Students learn the concept of the conservation of energy via a “collision,” and will realize that with friction, energy is converted primarily to heat to slow and stop an object in motion. In the associated activity, “The Puck Stops Here,” students will investigate the frictional force of an object when different materials are placed between the object and the ground. This understanding will be used to design a new hockey puck for the National Hockey League.

Engineers often try to limit the loss of energy to heat to create the most efficient systems possible. By limiting friction and creating more efficient systems, less energy is required to obtain the same result. When friction converts energy into heat, it is almost always considered “wasted” in a system.Identify the frictional force and how it acts to slow an object in motion. Explain the conservation of energy both when friction is present and when it is limited by the hover pucks. Explain the concept of inertia and how it relates to a puck sliding on the floor. Explain that friction slows down motion, because of the transfer of kinetic to heat energy. Explain why an engineer must understand friction when designing a hockey puck. 30TeachEngineering.orgGreg LarkinAnne VanderschuerenS1028406North_CarolinaScience4.01 Determine the motion of an object by following and measuring its position over time.55S1028407North_CarolinaScience4.02 Evaluate how pushing and pulling forces can change the position and motion of an object.55S1028408North_CarolinaScience4.03 Explain how energy is needed to make machines move.&#8226; Moving air.55S102840ANorth_CarolinaScience4.04 Determine that an unbalanced force is needed to move an object or change its direction.55S102840BNorth_CarolinaScience4.05 Determine factors that affect motion including:<br />&#8226; Force.55S102840FNorth_CarolinaScience4.06 Build and use a model to solve a mechanical design problem.&#8226; Devise a test for the model.55United StatesCopyright 2012 - Engineering K-Ph.D. Program, Pratt School of Engineering, Duke Universityhttp://www.teachengineering.org/policy_ipp.phphttp://www.teachengineering.org/2008-09-265Teacher