ENERGY Energy is the capacity for doing work or to produce heat. Energy cannot be created or destroyed, it can only be transformed from one form into another. Types of material systems depending on the transference: Open system: You are able to exchange matter and energy. Closed system: You can exchange energy (as heat or work), but not matter. Isolated system: You can’t exchange any of heat, work, or matter with the surroundings. Heat and work can produce transformations in matter.
A body has: Potential Energy: stored energy. Energy Kinetic Energy: the energy of motion. Ex: A roller Energy coaster. Substances like wood, coal, oil, and gasoline have stored energy because of their chemistry they can burn.
FORMS OF ENERGY Mechanical Electrical Thermal Electromagnetic Chemical Nuclear Internal Energy can be transferred, or converted, from one form to another!
MECHANICAL ENERGY Energy associated with the motion of an object. (Kinetic and potential energy) Chewing Frog Dancing
THERMAL ENERGY Total energy of the particles in a substance or material. All objects give off thermal energy Ice cream melting gains thermal energy
CHEMICAL ENERGYPotential energy stored in chemical bonds. Food Fire Cracker Stomach Battery
INTERNAL ENERGYIt is the total energy contained by a body, related to atoms, molecules etc.
ELECTRICAL ENERGY Moving electrical charges that produce electricity and energy. Lightening Batteries
ELECTROMAGNETIC ENERGY Energy that travels in waves Visible light UV Rays Microwaves Radio
NUCLEAR POWER Energy stored in the nucleus of an atom from fission or fusion Sun Stars Nuclear Power Plant
SOURCES OF ENERGY Renewable energy: It comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat. Non-renewable energy: resources which can’t be used again and again because they run out. Ex: Fossil fuels.
ACTIVITIES1.What happens during any change?2.Write an example of open, closed and isolated system.3.What type of material system (open, closed isolated) is a pressure cooker with food inside which is being heated: a) Before the security valve expels water vapour. b)When the security valve expels water vapour.4. What’s energy?5.Two bodies, A and B, are isolated from the environment. If body B gains 500 J of energy, what has happened to body A?
6.Name the type of mechanical energy a body has when:a) It’s at rest on the top of a roof.b) It reaches the ground at a speed of 3 m/s.7.What’s a nonrenewable source of energy? And renewable? Give examples of both.8.In what units are heat and work measured?9.Fill in the blanks using these words: joules- transformed-energy-material system-destroyed- same._______is the capacity that a _______ has to produce changes. Energy is measured in______ In any energy transfer, the total amount of_______ before the transfer remains the__________ as the total amount of_______afterwards. Energy is not______or________, it’s just___________.