Work, Energy and Power
In physics, mechanical work is the amount of energy transferred by a force. Like energy, it is a scalar quantity, with SI units of joules. Heat conduction is not. Three variables are of importance in this definition - force, displacement, and the extent to There is a relationship between work and total mechanical energy. Energy can be defined as the capacity for doing work. The simplest case of mechanical work is when an object is standing still and we force it to move.Power - Work and energy - Physics - Khan Academy
In solving work problems, one must always be aware of this definition - theta is the angle between the force and the displacement which it causes. If the force is in the same direction as the displacement, then the angle is 0 degrees.
If the force is in the opposite direction as the displacement, then the angle is degrees. If the force is up and the displacement is to the right, then the angle is 90 degrees. This is summarized in the graphic below.
Work, Power, and Energy
Power Power is defined as the rate at which work is done upon an object. Like all rate quantities, power is a time-based quantity.
Power is related to how fast a job is done. Two identical jobs or tasks can be done at different rates - one slowly or and one rapidly.
Work and energy | Physics | Science | Khan Academy
The work is the same in each case since they are identical jobs but the power is different. The equation for power shows the importance of time: Special attention should be taken so as not to confuse the unit Watt, abbreviated W, with the quantity work, also abbreviated by the letter W.
Combining the equations for power and work can lead to a second equation for power. A few of the problems in this set of problems will utilize this derived equation for power. Mechanical, Kinetic and Potential Energies There are two forms of mechanical energy - potential energy and kinetic energy.
Potential energy is the stored energy of position. In this set of problems, we will be most concerned with the stored energy due to the vertical position of an object within Earth's gravitational field.
Kinetic energy is defined as the energy possessed by an object due to its motion. Types of Energy There are two types of energy in many forms: When a neutron splits an atom's nucleus into smaller pieces it is called fission. When two nuclei are joined together under millions of degrees of heat it is called fusion Electrical Energy --The generation or use of electric power over a period of time expressed in kilowatt-hours kWhmegawatt-hours NM or gigawatt-hours GWh.
Chemical Energy --Chemical energy is a form of potential energy related to the breaking and forming of chemical bonds. It is stored in food, fuels and batteries, and is released as other forms of energy during chemical reactions.
Work, Power, and Energy - Wikiversity
Mechanical Energy -- Energy of the moving parts of a machine. Also refers to movements in humans Heat Energy -- a form of energy that is transferred by a difference in temperature What is Power Power is the work done in a unit of time. In other words, power is a measure of how quickly work can be done.
One common unit of energy is the kilowatt-hour kWh. Change in KE means you have accelerated the object. When you accelerate an object, you are changing its velocity and thus its KE.
Work and energy
By accelerating the object over a period of time, you are moving the object some distance, while changing its veleocity. Thus, you arwe doing work against inertia you are doing work against inertia, such that the work equals the change in kinetic energy of the object.
When you are doing work against continuous resistive forces, such as gravity or spring tension, work done equals the change in potential energy of the object.
Questions you may have include: What is the equation for work?