Could a star ever move in retrograde motion? Would you ever expect a star to significantly change its position in the sky relative to other stars and constellations? Why does a planet that we can observe with the naked eye do these things while stars do not?

Consider two oppositely charged, isolated parallel plates separated by distance D, with capacitance C, charge Q, and stored energy U. D is small compared to the dimensions of the plates. For each statement below, select "True" or "False".

1. Because of energy conservation, inserting a dielectric leaves U unchanged.
2. When D is halved, Q stays the same.
3. Inserting a dielectric decreases C.
4. When D is doubled, U increases.
5. When D is doubled, C is doubled.
6. Inserting a dielectric increases Q.
7. Increasing D, leaves the E field unchanged.

A conducting sphere is placed within a conducting spherical shell as shown in the figure below. The conductors are in electrostatic equilibrium. The inner sphere has a radius of 1.50 cm, the inner radius of the spherical shell is 2.25 cm, and the outer radius of the shell is 2.75 cm. The inner sphere has a charge of 225 nC, and the spherical shell has zero net charge.

When consulting manuals, electricians, online sources, etc., they always instruct you to handle halogen light bulbs with gloves.

The "explanation" that usually accompanies this statement is that oils and salts from a bare hand can "react" with the surrounding glass/quartz, owing to the fact that halogen bulbs are much hotter than ordinary ones. These reactions would cause weak spots in the quartz (or in some versions of the story, the filament), decreasing the lifetime of the bulb.

Is there any merit to this explanation? What are then the precise mechanisms involved in the bulb's degradation when the bulb is touched by a dirty monkey finger?

What maximum output would you expect from a wind turbine with a blade of radius 15 ft in a 25 mph wind

A liquid has a density at 289K of 955kg/m^3. Its(volume) thermal expansion coefficient is 1.05E-3/K. What is its density at 316K? Answer 929 kg/m^3 I'd appreciate explanation ! Thank you :)

1. Although quantum information has been around for a long time, we are starting to see more about it in the media

A parallel-plate air-filled capacitor has a capacitance of 335 pF. If each of its plates has an area of 0.025 m², what is the separation? If the region between the plates is now filled with germanium, what is the capacitance?

Our sun will first become a red giant star when it leaves the Main Sequence, as it goes from core Hydrogen burning to shell Hydrogen burning. After it has exhausted all of the fusion reactions possible, perhaps some Helium fusion in there as well, it will leave a corpse called a White Dwarf, where there is a crystalline core of carbon and mixed ash products, surrounded by

1. By using the formula for the Electric Field, calculate Electric field of a solidnonconducting sphere with radius R, and charge Q distributed uniformly on the sphere, at any point a distance r from the center of the sphere for r > R and r < R.

2. By using the formula for the Electric Field, calculate Electric Field of a conductingsphere with radius R and charge Q distributed uniformly on the sphere, at any point a distance r from the center of the sphere for r > R and r < R.

How does specific heat affect the weather? Give three examples of weather phenomena that are affected by the specific heat of land, oceans and air

The resting surface charge density of a membrane is 0.5 uC/cm^2. The resting membrane potential is 0.5 V. It drops to 0 V in 5 ms. If there are 25 Na channels per um^2 that open up during depolarization, what is the average current that flows through a sodium channel during this time (5 ms)? How many sodium ions move through the channel in 5 ms?