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This module presents the basic idea of a model to be used in the physical sciences, social sciences, and engineering. Perhaps also in the humanities.

Models

The concept of a model is very close to that of an analogy. It is so fundamental to our thought, decisionmaking, and problem solving processes that it is difficult to isolate and study; however, to accomplish the goal of simulatingand understanding complicated social systems, it is essential that we do understand the concept of a model and develop methods forconstructing them. Like many basic concepts, it is best described by examples:

Physical model

To the average person the word "model" might bring to mind someone modeling a dress, or perhaps a photographer'smodel, or even a model airplane or car. Let's consider these cases. The usual reason for looking at a dress on a model is to imaginewhat the dress would look like on one's self without having to buy it to find out. The photographer uses his camera to make a likenessof the model in the form of a picture. The model plane or car allows one to enjoy the details and perspectives of the modelwithout the problems and expense of actual ownership of the airplane or car. Indeed, one can try experiments on the models thatwould be very difficult or expensive to actually perform on the real thing.

Consider the methods and purposes behind the architect's model of a building, the car designer's prototype of anew design, or the aerodynamicist's wind tunnel model of a new airplane. As one considers what is common to these ideas of a modeland what purposes are served, perhaps the concept begins to take shape.

Mental model

Rather than further pursue the various types of physical models, let us consider another less obvious form ofmodel, the mental model. For example, the merchant who mentally speculates: "if I increase the price of this article from x to y,the buyers will still buy enough that I will come out ahead," and the mother who says, "if I spank my child for leaving his toys out,he will stop", are both using intuitive mental models of incredibly complicated economic, sociological, and psychological systems thateven experts don't agree on. Freud, Skinner, Erikson and others have all produced models of human psychology that much of moderntherapy and advertising are based on. Indeed, reflection indicates that much of human thought is involved with mental model making andthe use of these models for decision making, problem solving, or merely pleasure.

The politician who tells the voters what will happen if certain policies are followed, the advertiser who tellsthe potential buyer the results of using his product, and the preacher who predicts the consequences of evil to his followers areall involved with the building and use of mental and verbal models.

Even the simple speculation of "if I wear these clothes I will look nice" is based on a model of how one'sfriends will respond to one's dress. Indeed, most processes of experience can be viewed as model building, experimentation, modelmodification, etc. Further reflection shows how much of one's mental activities can be viewed as involved with modeling and howmany academic disciplines are based on models, even though the concept and process is poorly understood and seldom explicitlydiscussed.

Questions & Answers

Three charges q_{1}=+3\mu C, q_{2}=+6\mu C and q_{3}=+8\mu C are located at (2,0)m (0,0)m and (0,3) coordinates respectively. Find the magnitude and direction acted upon q_{2} by the two other charges.Draw the correct graphical illustration of the problem above showing the direction of all forces.
Kate Reply
To solve this problem, we need to first find the net force acting on charge q_{2}. The magnitude of the force exerted by q_{1} on q_{2} is given by F=\frac{kq_{1}q_{2}}{r^{2}} where k is the Coulomb constant, q_{1} and q_{2} are the charges of the particles, and r is the distance between them.
Muhammed
What is the direction and net electric force on q_{1}= 5µC located at (0,4)r due to charges q_{2}=7mu located at (0,0)m and q_{3}=3\mu C located at (4,0)m?
Kate Reply
what is the change in momentum of a body?
Eunice Reply
what is a capacitor?
Raymond Reply
Capacitor is a separation of opposite charges using an insulator of very small dimension between them. Capacitor is used for allowing an AC (alternating current) to pass while a DC (direct current) is blocked.
Gautam
A motor travelling at 72km/m on sighting a stop sign applying the breaks such that under constant deaccelerate in the meters of 50 metres what is the magnitude of the accelerate
Maria Reply
please solve
Sharon
8m/s²
Aishat
What is Thermodynamics
Muordit
velocity can be 72 km/h in question. 72 km/h=20 m/s, v^2=2.a.x , 20^2=2.a.50, a=4 m/s^2.
Mehmet
A boat travels due east at a speed of 40meter per seconds across a river flowing due south at 30meter per seconds. what is the resultant speed of the boat
Saheed Reply
50 m/s due south east
Someone
which has a higher temperature, 1cup of boiling water or 1teapot of boiling water which can transfer more heat 1cup of boiling water or 1 teapot of boiling water explain your . answer
Ramon Reply
I believe temperature being an intensive property does not change for any amount of boiling water whereas heat being an extensive property changes with amount/size of the system.
Someone
Scratch that
Someone
temperature for any amount of water to boil at ntp is 100⁰C (it is a state function and and intensive property) and it depends both will give same amount of heat because the surface available for heat transfer is greater in case of the kettle as well as the heat stored in it but if you talk.....
Someone
about the amount of heat stored in the system then in that case since the mass of water in the kettle is greater so more energy is required to raise the temperature b/c more molecules of water are present in the kettle
Someone
definitely of physics
Haryormhidey Reply
how many start and codon
Esrael Reply
what is field
Felix Reply
physics, biology and chemistry this is my Field
ALIYU
field is a region of space under the influence of some physical properties
Collete
what is ogarnic chemistry
WISDOM Reply
determine the slope giving that 3y+ 2x-14=0
WISDOM
Another formula for Acceleration
Belty Reply
a=v/t. a=f/m a
IHUMA
innocent
Adah
pratica A on solution of hydro chloric acid,B is a solution containing 0.5000 mole ofsodium chlorid per dm³,put A in the burret and titrate 20.00 or 25.00cm³ portion of B using melting orange as the indicator. record the deside of your burret tabulate the burret reading and calculate the average volume of acid used?
Nassze Reply
how do lnternal energy measures
Esrael
Two bodies attract each other electrically. Do they both have to be charged? Answer the same question if the bodies repel one another.
JALLAH Reply
No. According to Isac Newtons law. this two bodies maybe you and the wall beside you. Attracting depends on the mass och each body and distance between them.
Dlovan
Are you really asking if two bodies have to be charged to be influenced by Coulombs Law?
Robert
like charges repel while unlike charges atttact
Raymond
What is specific heat capacity
Destiny Reply
Specific heat capacity is a measure of the amount of energy required to raise the temperature of a substance by one degree Celsius (or Kelvin). It is measured in Joules per kilogram per degree Celsius (J/kg°C).
AI-Robot
specific heat capacity is the amount of energy needed to raise the temperature of a substance by one degree Celsius or kelvin
ROKEEB
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Source:  OpenStax, Dynamics of social systems. OpenStax CNX. Aug 07, 2015 Download for free at https://legacy.cnx.org/content/col10587/1.9
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