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The Origins of Physics; Physics of the Ancient Greek Era; Poetry Influenced by the Scientific Revolution; The Concept of Energy; Thermodynamics and the. I wrote a lot of songs about you I'll probably write a lot more But my future is brighter .. You had my heart and you took it, My soul, my energy, my love How could you? .. At 13, I first felt it The briskness of butterflies The heat of spring A seed was .. shines even when you are in despair The way you work hard even when. No phone calls receivedNo morning runNo drive to work that dayNo reply to ( poems go here) Blood shutter eyes Can't seem to find the light, Prisoner inside a box In the middle of this special relationship, a special bond which grew? . In the end we are only dust blending in, the essence and energy of our youth lost.
So many words and so little said, no?
Work as the transfer of energy
Actually, quite the contrary. This definition is so compact it's like poetry. It says as much as it can in as few words as possible. It's so compact that explaining it in ordinary language makes the half dozen words of the technical definition expand to nearly a hundred words of so-called "natural language". Let me explain what work is though a series of mental images.
Whenever an example is presented, remember that work is done whenever a force causes a displacement. Imagine that a physics teacher is standing motionless before a class of students.
Since he isn't exerting any forces that will displace anything outside of his body he isn't doing any work. But doing this for any length of time will certainly drain him of energy just as if he pushed papers across his desk all day an example where a force does result in a displacement. Surely, you could now convince him that his definition of work must be wrong. Maybe a lesser teacher would cave under the pressure, but not a physics teacher.
Most certainly, a physics teacher or any other person standing is doing work, but the work being done isn't easily visible.
Inside the body the heart is pumping blood, the digestive system is grinding away on breakfast, receptors are driving molecules across cell membranes. We do work even as we sleep.
WORK, ENERGY AND POWER
Forces causing displacements are happening everywhere under our skins. The human body is a busy place. A physics teacher pushing papers across his desk is doing external work. A physics teacher standing motionless is not doing any significant external work.
A physics teacher thinking deeply or lying in a coma is doing internal work. Extra credit if you can tell the difference between the two.
A physics teacher doing anything — or nothing for that matter — is doing internal work. A physics teacher who is dead is not doing any work, internal or external. In mechanics, when we say work has been done we are often referring to external work.
Now that we've decided that a teacher standing still isn't doing any work, let's imagine a teacher moving around and ask if work was done. Hmm, well anytime arms and legs get moving the situation is moderately complex. This makes it hard to identify what it is about the motion that involves work and what doesn't. We need to simplify things a little bit more.
Give the teacher a book like a physics textbook and ask him to move the book around in a few simple ways. The question now is, "Did the teacher do any work on the book?
For a teacher holding a book, or any other system for that matter, work is done whenever a force results in a displacement. Consider the following six examples presented three at a time.
No work is done on a textbook when it is held at rest. Positive work is done on a textbook when it is raised vertically at a constant velocity. Positive work is also done on a textbook when it is raised diagonally at a constant velocity. The first example makes obvious sense. Holding a book without moving it surely results in no work being done on the book. Replace the teacher with a table or the floor.
A book lies on the floor. What work is the floor doing? Nothing is going anywhere. Nothing is being done — not even work. The second and third examples also make sense. The teacher pushes on the book and it moves. A force resulted in a displacement. This agrees with our everyday notion of work. All is right with the world. Let's look at three more examples. No work is done on a textbook when it is carried horizontally at a constant velocity.
Negative work is done on a textbook when it is lowered diagonally at a constant velocity. Negative work is also done on a textbook when it is lowered vertically at a constant velocity. The first one in this set is bothersome. It basically says that no work is done carrying a book across level ground. It's so patently stupid it must be wrong — right?
You have to read this last bit as an internal dialog for it to make sense. 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.
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.Force, Work and Energy for Kids - #aumsum #kids #education #science #learn
In other words, power is a measure of how quickly work can be done. One common unit of energy is the kilowatt-hour kWh. If we are using one kW of power, a kWh of energy will last one hour. Power's unit of measurement in the English system is the horsepower, which is equivalent to How much work is done? Please enter your answer in the space provided: How much power is used?
An example of Kinetic Energy would be: