Why Should we Work?(Give some reasons)
What Is Work?Work is the action of energy on living and on non living matter which produces a result that can be useful to us.
But what is energy?Energy can take many forms; there are physical or mechanical energy, chemical energy, thermic or heat energy and atomic energy.As an example of mechanical energy that produces work, we have the motion of our body or of the parts of it (motion of the arm, that of the leg, etc.). Another example of mechanical energy is the motion of the wind. Therefore, energy, in classical physics, can be said to be the motion of matter, and when this motion is transfered to other matter it can perform some work. However, there are some instances where matter is about to move, withouth having moved yet, and this is also called energy. In the first examples, it was kinetic energy; in the later instances, it is potential energy.
Is energy related to force?The answer is Yes. Force is merely directional energy; it is why it is often represented by an arrow (--->). If I push against the wall, I exert a force against it and this force is my muscular energy directed against the wall. However, the wall does not move; it resists my push. How will you call the force exerted by the wall against my arm?Resistance is that force. Any counteracting force, any opposite force against an initial one is a resistance, and we can represent it also by an opposite arrow separated from the initial one by the wall (--->||<---) We have described and defined work, energy, force and resistance, and now we are eager to know what is power and if it is in anything related to those.
What is Power?Power is any given work in a unit of time. Hence, if we have worked for two hours, the power we spent should be equal to the work done divided by the two hours. In mathematical forms, it can be written:
The Human Body as a Machine at WorkHow do you conceive it? Give me some examples using the notions of force, energy or even power. .... Suppose I walk to the door. To move to that distance I have to lift my legs and move my body weight; therefore I have to push my legs against the ground, to exercise a force against it and I have to use this force all the way on my distance to the door. We can thus write:Do you know something (an organ) in the human body that never stops working? .,,,The heart is such an organ.
Now You Know!Let us resume. Work is the action of energy on living and on non living matter, producing a result. Energy is itself the motion of matter ("Energy is matter," Einstein said "and matter is energy"), energy can be kinetic or potential and can take many forms. Force is directional energy. Resistance is a counteracting force, like gravity is. And Power is work in any given unit of time. |