chapter 3 vocab Flashcards
energy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changes
conservation of energy
the work output of any machine cannot exceed the work input. In an ideal machine, where no energy is transformed into thermal energy
conservation of energy for machines
the percentage of the work put into a machine that is converted into useful work output
efficiency
a collision in which colliding objects rebound without lasting deformation or the generation of heat
elastic collision
the property of a system that enables it do work
energy
a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent
fuel cell
the product of the force acting on an object and the time during which that force acts on that object
impulse
a collision in which the colliding objects become distorted, generate heat, and may even stick together
inelastic collision
energy of motion, quantified by the relationship
kinetic energy
In the absence of an external force, the momentum of a system remains unchanged. Hence, the momentum before an event involving only internal forces is equal to the momentum after the event
law of conservation of momentum
a simple machine consisting of a rigid rod pivoted at a fixed point called the fulcrum
lever
a device, such as a lever or pulley, that increases (or decreases) a force simply changes the direction of a force
machine
inertia in motion, given by the product of the mass of an object and its velocity
momentum
the energy that matter possesses due to its position
potential energy
the rate of doing work
power
