Chpater 12 Work And Energy Flashcards
Work
Energy transfer to a body by a force that makes a body move to the direction the force moves it to.
Power
Measures rate work is done
Mechanical advantage
Measure the amount a machine multiples distance orforce
Joule
Work measured in Newton’s times meters these units called joules
Watt
Power’s SI unit
Simple machine
Most basic machine out of six types of machines
Compound machines
Machine that has more than on simple machine built into it
Lever
Claw hammer pulling out nail. Claw does work on nail
First class lever
Have a fulcrum that is between the points of application of the input and output forces
Second class lever
Fulcrum at one end and input force is put on other end
Third class lever
Multiply distance instead of force so third class levers have mechanical advantage less than one.
Pulley
Helps lift things also simple machine in the lever family
Block and tackle
A hunch of pulleys put together in a single unit
Wheel and axle
Lever or pulley that is connected to a shaft. Simple machine
Inclined Plane
Turns small input force to large output force by spreading out the work over a big distance
Wedge
Simple machine in inclined family that functions like two inclined planes back to back.
Screw
Inclined plane wrapped around a cylinder
Potential energy
Energy object has because of shape, position, or condition
Mechanical energy
Amount of work object can do because of its kinetic and potentially energies
Kinetic energy
Energy that object has when moving
Elastic potential energy
Stored up energy in stretchy material
Gravitational potential energy
Stored energy in object above the ground
Nonmechanical energy
Energy lies at level of atoms and doesn’t affect motion
Efficiency
Measures ratio of useful work output to work input
