Section 20: Forces And Energy Flashcards
what is energy
energy is transferred whenever things happen. energy is transferred between stores.
energy stores
kinetic
thermal
chemical
gravitational potential
elastic potential
electrostatic
magnetic
nuclear
how can energy be transferred
energy can be transferred between stores:
mechanically
electrically
heating
radiation
when a system changes, energy is transferred
how does energy transfer when a system change
it can be transferred into or away from the system between different objects in the system or between different types of energy stores.
whenever a system changes some energy is dissipated and stored in a less useful way.
how can energy be transferred by heat
a pan of water is heated on a camping stove. when the system is the pan of water, energy is transferred into the system by heating to the thermal energy stores of the pan and the water, which increases the temperature.
how is energy transferred by doing work
a box is lifted up off a floor so the box is the system, as the box is lifted work is done. this causes energy to be transferred to the box’s kinetic and gravitational potential energy stores
how is energy transferred by electrical equipment
electrical devices work by transferring energy between different energy stores.
what is work done
when a force moves on an object through a distance WORK IS DONE on the object and the ENERGY IS TRANSFERRED
how to calculate work done
work done= force x distance moved in the direction of force.
E=Fd
