PHIL 1050 Lecture : Jan 19 Lecture Note

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azurecrow744

17 Dec 2011

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Document Summary

Aristotle described 14 valid forms of syllogistic argument. There are 4 possible quantifiers, any of which can attach to any sentence in a syllogism of any figure. 4 options of quantifier for the first, second and third sentence therefore there are 4x4x4 = 64 distinct syllogistic forms in each figure and since there are 4 figures; there are 256 distinct forms of syllogistic arguments altogether. Aristotle held that the valid syllogisms of the first figure are perfect, by which he meant that their validity is obvious and self-evident & requires no proof. To show the first, aristotle assumed certain rules of conversation, which are really logical rules for inferring one sentence from another. Rule 1: from no x are y infer no y are x . Rule 2: from all x are y infer some y are x . Rule 3: from some x are y infer some y are x .

Related Questions

A small toy (which is often foundin party crackers) consists of a plastic or wooden figure attachedto a spring. The bottom of the figure contains a suction devicewhich will hold it to a smooth surface when the spring iscompressed (see Figure 1).

When the toy is pressed down and made to stick to a glass table,the total compression of the spring is 1.2 cm, and the centre ofmass of the toy is assigned a vertical coordinate z = 0 cm. After ashort time the suction device fails and the toy pops up verticallyinto the air, with the centre of mass of the toy reaching a maximumheight at z = 34 cm. It then falls back down onto the table. In thefollowing, assume that the mass of the spring can be neglectedcompared to the other parts of the toy.
Describe (in words and in a few sentences) the energy conversionsthat take place from start to finish during this process. (Ignoreair resistance and all forces and energy associated with theoperation of the suction device.)

If the total mass of the toy is 0.65 g and assuming that the springis ideal and that air resistance and other losses are negligible,calculate the spring constant of the spring. (Take g = 9.81 msâ2.)
What is the magnitude of the force that has to be applied in orderto compress the spring sufficiently so that the toy can be presseddown to the table?
Calculate the speed with which the toy leaves the table.

The kinetic theory of gases states that the kinetic energy of a gas is directly proportional to the temperature of the gas. A relationship between the microscopic properties of the gas molecules and the macroscopic properties of the gas can be derived using the following assumptions: The gas is composed of pointlike particles separated by comparatively large distances. The gas molecules are in continual random motion with collisions being perfectly elastic. The gas molecules exert no long-range forces on each other. One of the most important microscopic properties of gas molecules is velocity. There are several different ways to describe statistically the average velocity of a molecule in a gas. The most obvious measure is the average velocity Vavg. However, since the molecules in a gas are moving in random directions, the average velocity is approximately zero. Another measure of velocity is (V^2)avg, the average squared velocity. Since the square of velocity is always positive, this measure does not average to zero over the entire gas. A third measure is the root-mean-square (rms) speed,Vrms , equal to the square root of (V^2)avg. The rms speed is a good approximation of the the typical speed of the molecules in a gas. This histogram (Figure 1) shows a theoretical distribution of speeds of molecules in a sample of nitrogen () gas. In this problem, you'll use the histogram to compute properties of the gas.

Part A

What is the average speed

of the molecules in the gas?

Part B

Because the kinetic energy of a single molecule is related to its velocity squared, the best measure of the kinetic energy of the entire gas is obtained by computing the mean squared velocity, $(v^2)_{\rm avg}$ , or its square root. The quantityis more common than $(v^2)_{\rm avg}$ because it has the dimensions of velocity instead of the less-familiar velocity-squared.