what is the difference between linear and non linear law of physics?

Question

would prefer a nonmath narrative description

Answer 1

Linear means that the relationship between two variables varies in the same way, except by a constant factor (A) and a constant offset (B). y = A*x + B

The volume of water in a tank, and its mass are linearly related. [m = p*V, where m is the mass, p (rho) is the density of water, which is constant (converted to the units of m and V), and V is the volume of water. The units of m and V are usually kg and liters, or lbs and ft^3.]

Any other kind of relationship is non-linear, which includes most every process in the real world. Non-linear relationships usually seem to result from friction/entropy/inefficiency or from forces like magnetic fields, electric fields, or gravity, or well pretty much everything real.

Answer 2

Linear means whatever you put into a system simply comes out at different strength. Let's say you have a piano hooked up to a linear amplifier and put in the note middle C. You will only get the middle C tone ( weaker or stronger) out and if you put both an A note and a C note you will only get those two notes out. The fact that they come out at a different volume does not affect the "linear" part.

Non-linear says that what comes out may have very little relationship to the inputs. If you put in the C and the A notes, you may get, The A, the C and the difference and sum between the A and the C....

Linear systems in their simplest form multiply the input by a constant. Non-linear systems may involve squares or cubes or other crazy math functions acting on the inpui.

Answer 3

I think what you may mean, is the difference between the application of certain laws to linear, as opposed to non-linear systems? If so... If a system is linear, and there are several influences on it (forces, voltages, etc), you can determine the effect of each one individually, and get the overall solution by adding up those individual results. This is called the "principle of superposition." But if a system is NOT linear, this method can't be used. Here's an example. Suppose I have a spring which compresses linearly with a force applied to it. Suppose I apply a 3 pound force to it, and it compresses 3 inches. I then apply a 2 pound force to it, and it compresses 2 inches. I know that 5 pounds will compress it 5 inches. But if the spring is not linear, it will not compress 5 inches with a 5 pound force.

Answer 4

In linear physical relations, one property varies in direct proportion to another property. For example velocity and distance are linearly related: if you travel twice as fast, you go twice as far in the same amount of time. If you plot one vs the other on a graph the points fall on a straight line.

In non-linear physical relations the relation is not a direct proportionality. It may be related to the square of something. For example distance and the strenth of gravity follow an inverse square law: double the distance and the gravitational force is 4 (two squared) times weaker, triple the distance and it's 9 times weaker, etc. Or sometimes the relation can depend on some higher power (cubed, 4th power, etc.) or depend on the logarithm or the cosine, or whatever. If you plot one vs the other on a graph, the points do not fall on a straight line.

Answer 5

linear = predictable, as in a straight line having a beginning and an end.
In physics, relating to probability based on observability of a set path (as in a straight line).
non linear = 1) not linear, as in ordered chaos. unpredictable however observable in its unpredictability.

Answer 6

Not sure exactly what you want but going back several years to me high school days, circular motion creates a centrifugal force.