Law of Conservation of Energy:
·
Energy
cannot be created or destroyed.
In other words, the total amount of energy in the
universe is constant!
But energy can change forms over and over.
Light bulbs change
electricity into heat and light.
Cars (engines) change
chemical energy into heat and kinetic energy.
People change chemical energy
into heat, kinetic energy, and sound.
Mechanical Energy:
·
The total amount of potential and kinetic energy in a
system (KE + PE)
High PE Low KE
High KE
High KE
Friction:
Will the swing keep moving forever? No! Friction slows it
down by converting the KE into sound and
heat. But the total amount of energy stays the same.
