# Physics Assignments Homework

## Geometric Optics

Your reflection in the bathroom mirror, the view of the moon through a patterns seen in a kaleidoscope all of these are examples In each case the object that you’re looking at appears to be in than its actual position; your reflection is on the other mirror, the moon appears to be much closer when …

## POWER INPUT TO A SOURCE

POWER INPUT TO A SOURCE Suppose that the lower rectangle in Fig. 26-19a is itself a source, with an emf larger that of the upper source and with its emf opposite to that of the upper source. Figure 26-20 shows a practical example, an automobile battery (the upper circuit element) ing charged by the car’s alternator (the lower …

## RESISTANCE

RESISTANCE obeyed, p is constant and independent of the magnitude of the indirectly proportional to 1. Often, however, we are more interested in a conductor than in1and more interested in the potential difference the conductor than in E. This is so largely because current and diffidence are much easier to measure than are 1 and E.  conductor is a wire …

## CURRENT

CURRENT A current is any motion of charge from one region to another. In this seetion e’ll discuss currents in conducting materials. The vast majority of technological applications of charges in motion involve currents of this kind. In electrostatic situations (discussed in Chapters 22 through 25) the electric field is zero everywhere within the conductor, and there is no current. However, this …

## INDUCED CHARGE AND POLARIZATION

INDUCED CHARGE AND POLARIZATION When a dielectric material is inserted between the plates while the charge is kept constant, the potential difference between the plates decreases by a factor K. Therefore the electric field between the plates must decrease by the same factor. If Eo is the vacuum value and E is the value with the dielectric, then E …

## FIELD OF ELECTRIC DIPOLE

Now lets think of an electric dipole as a source of electric field. What does the field look hape of things is shown by the field map of Fig. 22-22b. At each point the total E field is the vector sum of the fields from the two individual in Example 22-9. We suggest you try drawing diagrams showing …

## THE DECIBEL SCALE

In this equation l is a reference intensity, chosen to be 10-12 W/m2, approximately the hearing at 1000 Hz. Recall that “log” means the logarithm to the nsity levels are expressed in decibels, abbreviated dB. A decibel is L, named for Alexander Graham Bell (the inventor of the telephone). The large for most purposes, and the decibel is the usual …

## Wave Interference and Normal Modes

INTRODUCTION When a wave strikes the boundaries of its medium, all or part of the wave is reflected. When you yell at a building wall or a cliff face some distance away, the sound wave is reflected from the rigid surface, and an echo comes back. When you flip the end of a rope whose far end is …

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## ENTROPY AND DISORDER

ENTROPY AND DISORDER Entropy provides a quantitative measure of disorder. To introduce this concept, let’s consider an infinitesimal expansion of an ideal gas. We add heat dQ and let the gas expand just enough to keep the temperature constant. Because the internal energy of an ideal gas depends only on its temperature, the internal energy is also constant; …

## THE KELVIN TEMPERATURE SCALE

THE KELVIN TEMPERATURE SCALE In Chapter 15 we expressed the need for a temperature scale that doesn’t depend on properties of any particular material. We can now use the Carnot cycle to define sue scale. The thermal efficiency of a Carnot engine operating between two heat reserv at temperatures TH and Tc is independent of the nature of …