How much work does the electric field do in moving a proton from a point with a potential of +155V to a point where it is -50V ?

A) Express your answer in joules.

B) Express your answer in electron volts.

consider a simple situation: a 12.9kg crate slides rightward from rest without friction 3.2m down a ramp inclined 14.6

(1) In this problem, we will calculate the electric ?eld of a line charge. The line charge is aligned along the x-axis starting at the origin and having a length L. The line has a linear charge density ?. We want to ?nd the electric ?eld at a point P on the x-axis. The point P is located at the point pd,0q where d?L. (a) List all of the given parameters. (b) What is the dimensionality of a line of charge? What is the electric ?eld of a small charge dq which is one dimension less than our line? (c) What is the charge dq in terms of the given parameters? (d) What is the distance between an arbitrary point on our line charge to the point P in terms of given parameters? (e) What is the unit vector

A solid sphere 10 cm in radius carries a uniform 40-?C charge distribution throughout its volume. It is surrounded by a concentric shell 20 cm in radius, also uniformly charged with 40 ?C.

a)Find the electric field 5.0 cm from the center.

b)Find the electric field 15 cm from the center.

c)Find the electric field 30 cm from the center.

In one type of computer keyboard, each key holds a small metal plate that serves as one plate of a parallel-plate, air-filled capacitor. When the key is depressed, the plate separation decreases and the capacitance increases. Electronic circuitry detects the change in capacitance and thus detects that the key has been pressed. In one particular keyboard, the area of each metal plate is 47.0mm2 , and the separation between the plates is 0.670mm before the key is depressed.

Calculate the capacitance before the key is depressed.

If the circuitry can detect a change in capacitance of 0.230pF , how far must the key be depressed before the circuitry detects its depression?

A certain 8lb hunting rifle fires a 180 grain bullet at a target 1000yds away. The bullet experiences an acceleration of ?2.7 m s 2 (opposite direction of velocity) due to air resistance. When the bullet hits the target, its velocity is measured to be 820 m s . Express all answers in SI units. Helpful conversions:

1 grain = 6.48

You are working for a shipping company. Your job is to stand at the bottom of a 7.1m -long ramp that is inclined at 39? above the horizontal. You grab packages off a conveyor belt and propel them up the ramp. The coefficient of kinetic friction between the packages and the ramp is ?k=0.30.

2 A car with inertia 1200kg is driving through a parking lot. A wheeled platform of inertia 1800kg has just been unloaded from a flatbed truck. It gets away from them and is moving toward the car at a velocity of +2.5 m/s . The car cannot avoid it, and the two

Someone sent me this link to a talk by Prof. Klaus Schulten from the University of Illinois: (my emphasis)

Quantum Computing and Animal Navigation

Quantum computing is all the rage nowadays. But this type of computing may have been discovered and used by living cells billion of years ago. Nowadays migratory birds use a protein, Cryptochrome, which absorbs weak blue light to produce two quantum-entangled electrons in the protein, which by monitoring the earth's magnetic field, allows birds to navigate even in bad weather and wind conditions. The lecture tells the story of this discovery, starting with chemical test tube experiments and ending in the demonstration that the navigational compass is in the eyes and can be affected by radio antennas. The story involves theoretical physicists who got their first paper rejected as "garbage", million dollar laser experiments by physical chemists to measure the entangled electrons, and ornithologists who try to 'interrogate' the birds themselves. This work opens up the awesome possibility that room-temperature quantum mechanics may be crucial in many biological systems.

Now here's my question: What's the big deal with entangled electrons? I mean, if I do not neglect electron-electron interaction, then pretty much all electrons in a condensed matter system are entangled, are they not? Electrons in the same angular momentum multiplet are entangled via Hund's rule, electrons on neighboring sites in a tight-binding (or, in the interacting case, Hubbard) model can all be entangled due to an antiferromagnetic exchange coupling, etc. etc.

Sure, for a quantum computer I'd like to have physically separated electrons maintain their entanglement, and I'd like to have fine-grained control over which of the electrons are entangled in which way etc, but for chemical processes in molecules such as these earth-magnetic-field receptors, is it not a bit sensationalist to liken such a process to quantum computing?

Inspired by this question, are there any known planetary systems with largely varying planes of orbit? For example a system where two planets have perpendicular planes?

The velocity vector V1 has a magnitude of 5.0 m/s and is directed along the +x-axis. The velocity vector V2 has a magnitude of 4.0 m/s. The sum of the two is V3, so that V3 = V1+V2 Either True or false : The magnitude of V3 can be 9.0 m/s The x-component of V3 can be 5.0 m/s The magnitude of V3 can be -6.0 m/s The magnitude of V3 can be 5.0 m/s The magnitude of V3 can be 10.0 m/s The magnitude of V3 can be 0.0.

Following on Jim Graber's answer to: Can "big rip" rip apart an atomic nucleus?

If the cosmological constant is large enough, even the ground state of a hydrogen atom can be affected. So why is the energy scale for quantum gravity set by the planck mass and not by the cosmological constant? Is it because the cosmological constant can be associated with other theories (inflatons, or vacuum energies of the matter fields, etc.) and thus is just considered an ingredient and not gravity itself? If this does come down to a semantics issue, I'd still be interested to hear if the scale set by the cosmological constant suggests we may be able to see interesting quantum effects at that scale depending on what the cosmological constant 'is'.

A dielectric-filled parallel-plate capacitor has plate area A = 15.0cm2 , plate separation d = 5.00mm and dielectric constant k = 5.00. The capacitor is connected to a battery that creates a constant voltage V = 10.0V . Throughout the problem, use ?0 = 8.85

A jet with mass m = 1.2

the rod below is a uniformly charged semicircle of arc length .14 m. If the total charge on the rod is -7.50 muy c, magnitude and direction of the electric field at point O? Point O is in the center of the semicircle.