Power of attraction, armed force, gravitational force and lifting power. Powerhouse, force field, fuel and powerful action. Atomic power, power of healing, muscular power and mental power. Power lifter, expression of power, power food and power plant. Half-time workforce, wind power, bounce power. We encounter the notions of power and force time and again in everyday life – in their literal as well as in their figurative senses. These terms are omnipresent yet remain abstract.
Well then, what do force and power really mean?
These are terms derived from physics, with force referring to something that can cause acceleration or deformation of a body. Force is the power needed to get work done, in the process of which energy is consumed.
What causes forces to occur and how are they applied?
Force appears in four fundamental forms, also known as the basic forces of physics:
- Gravitational force
The first of these is of course gravitational force (gravity). It not only acts through the Earth onto us but also in the opposite direction. Even if the impacts may not be tangible, every mass in the universe attracts every other mass to it. Gravitational force is always attractive and is dependent not only on its mass but also on its distance from other masses. Its strength is inversely proportional to the square of the distance between them. This means that gravitational force has an infinite range.
Exchange particles, ‘gravitons’, have a relative strength of 10-38 and a range [m] of ∞.
- Electromagnetic force
The next force familiar to us from everyday life is electromagnetic force. This occurs wherever electrically charged particles interact, for example in electricity, radio waves or rays of sunlight. Electromagnetic force is caused by electrical charge and can attract (in the case of opposing charges) or repel (where charges share the same polarity). Their range is infinite and, like gravity, decreases at the square root of distance between charges.
Exchange particles, ‘photons’, have a relative strength of 10-2 and a range [m] of ∞.
- The weak force
Then we come to the weak force. This is very closely linked to radioactivity and causes our sun to produce light. The weak force is the force that enables elementary particles to transform themselves into one another (e.g. an electron can turn into a neutrino and a quark can transform itself into a different quark, a process known as beta decay, where a neutron turns into a proton). The weak force only occurs among sub-atomic particles and their range extends only to one thousandth of the diameter of a proton. Although essential to life, people are generally unaware of the existence of either the weak or the strong force.
Exchange particles, W+, W– and Z0 have a relative strength of 10-3 and a range [m] of 10-18.
- The strong force
The strong force is ultimately the one that holds atomic nuclei together. Quarks in each nucleus communicate with one another by exchanging gluons. The further they move apart, the greater the strong force becomes, and this holds these particles together. The strong force is the strongest of the four natural forces, but it only has the range of one atomic diameter.
Exchange particles, gluons, have a relative strength of 1 and a range [m] of 2.5*10-15
Our life is therefore determined by these four forces. At the present time, modern physics assumes that, before the Big Bang, only one elemental force commanded everything that occurred. During the expansion that accompanied the Big Bang, the four individual forces now familiar to us separated themselves. In actual fact, these four forces are four presenting forms of that one elemental force. If the Big Bang theory is correct, it follows that we should be able to describe the four forces within a shared theoretical framework – known as the ‘Theory of everything’.
…we are almost entirely unaware of the strong and weak forces. In contrast, we are very aware of the actions of the forces of gravity and electromagnetism. Either when lifting loads, measuring weights or securing bridges, whenever stresses arise in systems, or whenever we are quite simply in motion.
These forces can be measured. Forces can be measured on cranes, on lifting gear and on mobile machinery, in geo-technology, stage mechanics, mechanical engineering, medical technology and robotics: a force sensor can make a decisive contribution to saving you time as a customer because it can safeguard your investment by protecting against the possibility of mechanical failure.
So if you are wondering which force sensor is best suited to your application, which components provide measurement accuracy, safety and cost-effectiveness, or if you wish to find out how to save space, weight and therefore cost, then speak to us. The WIKA Group has almost 20 years of expertise in force measurement, and has the right answers to meet your challenges!