Chapter 12- Work And Energy Flashcards
Block and tackle
When multiple pulleys are combined together to act as one contraption.
Closed system
When the energy is too small and is ignored
Work
Transfer of energy to an object from a force causing the object to move in the direction of the force
Power
Quantity measuring the rate of work or transformed energy. Power=work/time
Mechanical advantage
Measures how much force or distance is multiplied by a machine. Mechanical advantage=output force/input force=input force/output force.
Joule
SI Unit of work. Newtonsmeters. Joules is also equivalent to 1kgm^2/s^2.
Watt
SI Unit of power. Abbreviation is W, not to be confused with work, italics W.
Simple machine
Basic types of machines that make up other forms of machines. Pulley, simple lever, simple inclined plane, wedge, screw, and wheel and axel.
Compound machine
Two or more simple machines put together to make a bigger machine. Like the brakes and tires of a bike.
Efficiency
Usually a percentage amount that measures useful work output to work input. Efficiency=useful work output/work input.
Elastic potential energy
Energy stored in stretchy or elastic material
First class lever
Has the fulcrum pointed at the middle of the arm.
Gravitational potential energy
Work of any two objects that have distance between them
Lever
An arm that has a Fulcrum(balance piece) attached.
Incline plane
An elevated platform, like a ramp.
Kinetic
The highest point and moving of an object
Non mechanical energy
Doesn’t affect a system on a large scale
Mechanical
Amount of work an object does because of the potential and kinetic energies
Perpetual motion machine
Theoretical machines that could go on forever without any input energy.
Open system
When energy flows freely
Pulls.
Modified levers that has a wheel of some kind on it.
Second class lever
Fulcrum at the end with the output force in the middle and the input force at the end opposite to the fulcrum
Potential energy
The lowest point
Third class lever
Fulcrum at the end, the input force at the middle and the output force at the opposite end from the fulcrum.
Screw
Incline plane wrapped around a cylinder to hold parts together.
Wedge
A piece that is forced into something to break apart. Like an axe splitting wood.
Wheel and axel
Made of a lever or pulley connected to a shaft. Normally used to mobilize an object.
