Ch5: Work, Energy, and Power Flashcards
Define work done by a force.
Product of the magnitude of the force and the distance moved by the object in the direction of the force.
Define the Joule.
One Joule is the work done when a force of 1N moves an object 1m in the direction of the force.
What is the SI base unit for joules?
J = Nm = kgm^2s^-2
Define elastic potential energy.
The energy stored as a result of a reversible change in an object’s shape.
Define electric potential energy.
The energy of charges due to their position in an electric field.
Define internal energy.
The sum of the randomly distributed kinetic and potential energies of the molecules in a substance.
Define electromagnetic energy.
The energy from electromagnetic waves, stored within oscillating fields.
State the principle of conservation of energy.
In a closed system, energy cannot be created nor destroyed, but only transferred from one form to another.
Define power.
The rate of work done. P=w/t
What is the equation for efficiency of energy output?
Efficiency (%) = useful output energy/total input energy x 100
