Intro to energy notes
- 1. Energy Holt: Chapter 9 Fusion: Unit 4
- 2. Energy • Energy conversion – when a form of energy is changed to another form of energy • Energy – ability to do work (also measured in joules) • Kinetic energy – energy in motion • The faster an object is moving the greater the kinetic energy, also the more mass an object has the greater the kinetic energy
- 3. • Potential – energy due to the objects position (object could move) • Gravitational potential energy – energy against the force of gravity—lifted objects have GPE • Mechanical energy – Has both kinetic + potential
- 4. • Law of conservation of energy – energy cannot be created or destroyed but can be changed from one form to another • Energy efficiency – the amount of useful energy after a conversion – the more efficient the more energy that can be used • Ex: shape of car, shape of plane, houses, windows
- 5. • Thermal energy – all the kinetic energy due to motion of particles that make up the object (faster the particles move the greater the thermal energy) • Chemical energy – energy of a compound that changes as its atoms are rearranged, a form of potential energy
- 6. • Electrical energy – energy of moving electrons, a form of potential energy since motion only happens when object is connected to actual output • Sound energy – vibrating object transmit energy through matter (S-L-G) • Light energy – vibration of electrically charged particles, doesn’t need to be carried through matter, can travel in a vacuum (area with no matter-- SPACE)
- 8. • Nuclear energy – energy from the change in the nucleus of an atom • Nuclear fusion – the joining of atoms (H) • Ex: when hydrogen is fused together at very high speeds to form helium (stars are nuclear reactors on a massive scale), the process releases tremendous amounts of energy
- 9. • Nuclear fission – the splitting of an atom • Ex: when uranium is split, the potential energy in the nucleus is given off and used in nuclear power plants to generate electrical energy
- 12. • Electrical – can be changed into thermal, sound, light and kinetic energy (most common energy used) • Energy conversions allow us to maintain our daily lives through machines • Conversion of energy always creates a certain amount of thermal energy for the transition to take place
- 13. • Chemcial: • Photosynthesis – light energy to chemical energy • 6CO2 + 6H2O + light energy → C6H12O6 + 6O2 • Cellular respiration – humans turning food (chemicals) into energy • C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP (energy)