Work, Energy, and Power. Work = W. The product of the force F applied to an object over a distance d in which the object travels as a result of the force. (Force and distance must be parallel to each other). Joule (J) is the base unit of work. Work Example.
Work, Energy, and Power
The product of the force F applied to an object over a distance d in which the object travels as a result of the force
(Force and distance must be parallel to each other)
Joule (J) is the base unit of work
A student lifts a 50 pound (lb) ball 4 feet (ft) in 5 seconds (s).
How many joules of work did the student complete?
Convert English units to SI units
Solve for Work
Ability to do work
Light, heat, mechanical, chemical, and electrical forms of energy can all be used to exert a force for a distance.
NASA solar sail
Potential Energy (Stored energy, usually referring to gravitational energy)
The capacity to do work by virtue of position or configuration
Kinetic Energy (Energy of motion)
Energy which a body possesses because of its motion, which occurs anywhere from an atomic level to that of a whole organism
Energy cannot be created or destroyed, but it can change from one form to another.
Changing one form of energy to another
Energy Efficiency: The ratio of the useful energy delivered by a dynamic system to the energy supplied to it
Entropy: The increasing disorder when energy is transformed to heat during conversion
Fossil fuelsChemical→ Heat→ Mechanical→ Electrical
NuclearNuclear →Heat→ Mechanical→Electrical
Vehicle System Conversion
Which output is desired, mechanical or heat?
What roles do engineers have in energy?
Rate at which work is performed or energy is expended
Watt is the base unit of Power
One watt is equal to 1 joule of work per second
Uses electrical energy to do work
Uses mechanical energy to do work (linear, rotary)
Uses energy transferred by liquids (hydraulic) and gases (pneumatic)
A student lifts a 50.0 pound (lbf) ball 4.00 feet (ft) in 5.00 seconds (s).
How many watts of power are used to lift the ball?
Work = 271.45 J
McGraw-Hill dictionary of engineering. (2nd ed.). New York, NY: McGraw-Hill.
Microsoft, Inc. (2008). Clip art. Retrieved January 10, 2008, from http://office.microsoft.com/en-us/clipart/default.aspx
National Aeronautics and Space Administration (NASA). (1997). Daedalus. Retrieved April 2, 2008, from http://www.dfrc.nasa.gov/Gallery /Photo/Daedalus/
U.S. Department of Energy. (2008). Scientific forms of energy. Retrieved March 23, 2008, from http://www.eia.doe.gov/kids/energyfacts/science/formsofenergy.html