2 Energy The ability to cause change Can take many different forms Kinetic - movingPotential - positionalThermal – Increases with heatChemical – stored in bondsRadiant – lightSound – vibration of moleculesElectrical – from electricityNuclear – stored in atomsSI unit is the joule (J)Energy and work are relatedEnergy is the ability to do work and work is the transfer of energy, therefore they are measured the same way!
3 Kinetic Energy (KE) The energy an object has due to its motion If an object isn’t moving it doesn’t have any KEDepends on both the mass and velocity of an object:If two objects have the same mass, the one travelling with greater velocity has more KEIf two objects are travelling the same velocity, the object with greater mass has more KE
4 Gravitational Potential Energy (GPE) The energy an object has due to its positionIf an object isn’t moving, it can still have GPEDepends on both the mass of the object and it’s height above the ground:If two objects have the same mass, the one that is higher up has more GPEIf two objects are positioned at the same height, the object with greater mass has more GPEKE and GPE are collectively referred to as Mechanical Energy
5 Potential Vs. Kinetic Energy Law of conservation of energy - energy cannot be created or destroyed.1.Potential energy = 50 JKinetic energy = 0 J2.Potential energy = 25 JKinetic energy = 25 J3.Potential energy = 0 JKinetic energy = 50 J
6 Thermal EnergyThe energy that all objects have that increases when the object’s temperature increasesDue to the motion of molecules that make up the objectEx. A cup of boiling water has more thermal energy than a cup of cold water, which has more thermal energy than a cup of ice.Usually is the last step in all energy transformations because it is so hard to store.
7 Chemical Energy The energy that is stored in chemical bonds Is released when bonds between compounds are brokenExamples of substances that contain chemical energy:WoodGasolineFood
8 Radiant Energy (Light Energy) Energy that is carried by lightCan be converted into thermal energy to warm objectsLight travels at 300,000 km/s, which is fast enough to circle the Earth eight times in one second.
9 Sound EnergyEnergy that is transmitted through a medium in the form of vibrations.Is a mechanical wave – requires material to travel through…cannot travel through a vacuum (No sound in space)The denser the material, the faster sound will travel (travels fastest in solids)
10 Electrical Energy Energy carried by an electrical current Caused by fast moving particlesThese particles have charges that attract or repel each other.
11 Nuclear Energy Energy contained in the nucleus of an atom Can be released two ways:fissionfusion