What is energy? Ability to do work or cause change –Work: ability to move an object some distance
General kinds of energy Energy fits into one of two categories: 1.kinetic energy or 2.potential energy
Kinetic energy Energy of motion –Also “released” energy”
Potential energy Stored energy –Energy at “rest”
Gravitational potential energy (G.P.E.) Amount of potential energy based on the mass and height of an object The higher the object is raised, the more potential energy it has The more mass an object has, the more potential energy it has
Measuring Kinetic Energy The faster the object, the greater the kinetic energy –K.E. = ½ x mass x velocity (speed) 2 If the mass increases, kinetic energy increases, but not as much as if the speed increases
What are the 5 Specific F orms of Energy ?
Mechanical energy energy of moving objects
Thermal (Heat) energy Energy of moving atoms
Electromagnetic energy Energy that travels in waves through space
Chemical energy Energy that is stored in bonds between atoms
Nuclear energy Energy released from the center of an atom –Fission and fusion of atoms
Forms of energy video Forms of energy video
Base your answers to questions 67 and 68 on the diagram below and on your knowledge of science. The diagram shows two students ready to dive into a pool. 67 Explain why student B has more potential energy than student A. [1] _______________________ 68 Student A dives from the board into the water. Explain why student A’s kinetic energy decreases as the student enters the water. [1] ______________________
Energy transformations Change from one of the 5 forms to another form to “transfer” energy
Base your answers to questions 69 through 72 on the illustration below and on your knowledge of science. The illustration shows a number of activities happening on a sunny day. 69 What is the original source of energy for all these activities? [1] ___________________________ 70 Identify one activity in the diagram that requires the use of fossil fuels. [1] ___________________________ 71 Identify one renewable resource shown in the diagram. [1] ___________________________ 72 An energy transformation occurs when one form of energy is changed to another. Fill in the spaces below to describe an energy transformation that occurs as the children play baseball. [1] __________________________ is changed to _________________
Transform between kinetic and potential Pendulum: a Pendulum: a pendulum continuously transforms energy from kinetic to potential energy and back.
Pendulum animation Pendulum animation
(Law Of) Conservation of Energy Energy cannot be created or destroyed, it is only transferred –Newton’s cradle –Bouncing ball –Energy Video: Conservation of Energy Conservation of EnergyConservation of Energy E=mc E=mc 2 – –Einstein’s theory of relativity