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?

Derive the formula for electron charge to mass ratio

e/m=2V/(Br)^2: first, explain why formulas

(mv^2)/r=evB and

eV=1/2mv^2 must hold. Then, do what algebra is necessary to show that those formulas imply formula e/m=2V/(Br)^2

1. An RLC series circuit has a 60 Ω resistor, a 3.5 mH inductor, and a 6 μF capacitor.
   1. Find the circuit’s impedance at 55 Hz and 12 kHz.
   2. If the voltage source has V_rms = 110 V, what is I_rms at each frequency?    

Two point charges are fixed on the y axis: a negative point charge q1 = -30 μC at y1 = +0.22 m and a positive point charge q2 at y2 = +0.37 m. A third point charge q = +9.8 μC is fixed at the origin. The net electrostatic force exerted on the charge q by the other two charges has a magnitude of 20 N and points in the +y direction. Determine the magnitude of q2.

37. Give two examples of different fossil fuels currently used today?

38.Explain how voice is changed into a fluctuating voltage in the early telephones?

39. What 1799 discovery allowed us to translate the ancient Egyptian hieroglyphs?

40.In the scientific method or process an explanation about natural phenomena with little or no experimental fact is called a ________________.

A diffraction grating has 25,000 lines/cm and is illuminated with light having a frequency of 5.0 x 10​14​ Hz. What are the angles of (a) the first-order bright fringe and (b) the second-order bright fringe?

An engineering students designs and builds a capacitor from some scrap iron. One piece of iron is a square with side lengths of 10 cm, while the other piece is a rectangle that is 20 cm long and 10 cm wide. The student knows they can keep the plates separated by a distance of 1.2 micrometers.

a. What is the capacitance of this setup?

b. If the capacitor is fully charged using a 1.5 V battery, how much charge is built up on the plates?

c. How much energy is stored?

d. After performing the experiment, the student inserts a dielectric with a k value of 1.2. What values would this change?

A disk-shaped merry-go-round of radius 2.63 m and mass 155 kg rotates freely with an angular speed of 0.570 rev/s. A 59.4-kg person running tangential to the rim of the merry-go-round at 3.82 m/s jumps onto its rim and holds on. Before jumping on the merry-go-round, the person was moving in the same direction as the merry-go-round's rim.

(a) Does the kinetic energy of the system increase, decrease, or stay the same when the person jumps on the merry-go-round?

(b) Calculate the initial and final kinetic energies for this system.