How was quark and hadrons discovered (partcile physics)

Consider a Fabry–Perot semiconductor laser diode operating at 1550 nm. The active region is a III–V quaternary semiconductor alloy of InGaAsP (but quite close to being InGaAs). The LD has a cavity length of 250 μm. The refractive index of InGaAsP is approximately 3.60 and dn/dT = 2.5 * 10^-4 K^-1, the linear thermal expansion coefficient is 5.6 * 10^-6 K^-1. The bandgap of InGaAs follows the Varshi equation Eg = Ego - AT^2>(B + T) with Ego = 0.850 eV, A = 4.906 * 10^-4 eV K^-1, B = 301 K. Find the shift in the optical gain curve, and the emission wavelength for a given mode per unit temperature change. What is your conclusion?

You have a tuning fork, called tuning fork A of unknown frequency. you know that when it vibrates, it has a maximum amplitude of 0.002ft. Tuning fork B, which has a period of 0.05s causes tuning for A to vibrate with an amplitude of 0.01ft. Tuning for C which has a period of 0.2s causes tuning fork A to vibrate with an amplitude of 0.015ft. What is the natural frequency of tuning fork A?

The capacitance of an object is a measure of how much charge separation can be produced on the object by applying a voltage difference to it, or contrarily, how much voltage arises across the object as a result of a particular charge separation developing. The equation defining the capacitance is

Q = C ΔV

where Q is the charge separation (+Q and -Q at two different places on the capacitor), C is the capacitance, and ΔV is the potential difference. But you can also read this equation from right to left: The capacitance also identifies how much voltage difference arises across the object as a result of a particular charge separation Q.

PART A: The unit we use for the capacitance is the Farad = 1 Coulomb/Volt. What is the dimensionality of the unit Farad (in terms of M, L, T, and Q -- mass, length, time, and charge)? (If you are not familiar with this idea, check out the pre-requisite webpages.) Express the unit Farad in terms of basic SI units (kilogram, meter, second, Coulomb).

A simulation of a lipid membrane imbedded in water (blue). Pastor, Venable, & Feller, Acc. Chem. Res. (2002) 35, 438-446.

PART B: A typical cell membrane in an animal maintains a potential difference across the membrane of ΔV = 70 mV and the membrane has a thickness of about 8 nm. The capacitance of the membrane is about 1 microFarad per square cm.  If we model the membrane by a simple "two thin sheets of charge" model separated by 8 nm with nothing between them, what would be the electric field be between the sheets and what would the charge density on the sheets of the membrane? Explain your reasoning.

PART C: Clearly, a membrane is not "empty" -- it's filled with lipid molecules as shown in the figure at the right. On the average, the dielectric constant, kappa, of the membrane is about 3. How would that change the average E field and the surface charge density that you found in part (B)?

PART D: In order to maintain the potential difference across the two sides of the membrane, cells carry ions across a membrane against the field ("uphill") using a variety of active transport mechanisms. One mechanism does so by using up some of the cell's stored energy converting ATP to ADP. How much work does it take to carry one sodium ion (charge = +e) across the membrane against the field? Calculate your answer in eV/ion, Joules/ion, and kilcalories/mole (the last for 1 mole of sodium ions).

Using what we know about the conjugate matrix, find the front principle plane for a thick lens with front and back radii of curvatures with a magnitude of 10.36 mm, a center thickness of 7.35 mm and an index of refraction of 1.45. What is the distance between the front surface of the lens and the principle plane in mm?

1. What happens if there is friction in the systems of an object attached to a spring?

Discuss mechanical energy under these conditions.

You are riding a stationary exercise bike. Assume the rear wheel is twenty0eight inches in diameter, the rear sprocket has a radius of two inches and the front sprocket has a radius of five inches. How many resolutions per minjute of the front sprocket produces a forward speed of forty milers per hour on the bike?

Why is empirical resistance higher than theoretical resistance? (Hint: what type of flow was Poiseuille modeling?)

- we used a rigid aorta and elastic aorta and measured the blood flow, pressure, resistance

An insulating sphere of radius a has charge density ρ(r) = ρ₀r², where ρ₀ is a constant with appropriate units. The total charge on the sphere is -3q. Concentric with the insulating sphere is a conducting spherical shell with inner radius b > a and outer radius  The total charge on the shell is +2q. Determine

(a) The magnitude of electric field at the following locations:

(i) r < a; ii) a < r < b; (iii) b < r < c; (iv) r > c.

(b) The total charge on the inner and outer surface of the shell.

(c) The surface charge density on the inner and outer surface of the shell.

(d) Extra credit: ρ₀ in terms of q, a, and the fundamental constants.

A freight train consists of two 8.1 x 10^4kg engines and 45 cars with average masses of 5.75 x10^4 kg each.

m=8.1x10^4kg

m2=5.75x10^4kg

f=7.25x10^5 N

Part (a): What is the magnitude of the force that each engine must exert backward on the track to accelerate the train at a rate of 5.00x10^-2m/s^2 if the force of friction is 7.6x10^5N, assuming the engines exert identical forces? This is not a large frictional force for such a massive system. Rolling friction for trains is small, and consequently trains are very energy-eficient transportation systems.

Part(b): What is the force in the coupling between the 37th and 38th cars (this is the force each exerts on the other), assuming all cars have the same mass and that friction is evenly distributed among all of the cars and engines?

I ALREADY ANSWERED PAT A NEED HELP WITH B

PART A) Define density parameter. Comment on the future of our universe based on the conditions of density parameter.

PART B)  The apparent magnitude of the star canopus is -0.72 and the its absolute magnitude is -3.1. Calculate the distance of the star in parsec. (Antilog (0.476) =2.99 and r is in parsec)

A 2.60×10⁴-kgkg rocket blasts off vertically from the earth's surface with a constant acceleration. During the motion considered in the problem, assume that gg remains constant. Inside the rocket, a 17.7-NN instrument hangs from a wire that can support a maximum tension of 37.6 NN .

A)Find the minimum time for this rocket to reach the sound barrier (330m/s) without breaking the inside wire.

B)Find the maximum vertical thrust of the rocket engines under these conditions.

c)How far is the rocket above the earth's surface when it breaks the sound barrier?

Which of the following systems demonstrates the least deformation? i. A 10 mm diameter, 1 m long copper cable made of copper raising a wet statue ii. A 5 mm diameter, 1 m long steel cable raising a wet statue iii. A 10 mm diameter, 1 m long steel cable raising a dry statue iv. A 10 mm diameter, 1.5 m long steel cable raising a wet statue v. A 10 mm diameter, 1 m long steel cable raising a wet statue

why?   



c. Rank the following according to the amount of heat absorbed to heat from 20 – 100°C? Rank i. A 169 kg wet statue why?   


ii. A 230 kg wet statue why?   


iii. A 230 kg dry statue why?   


iv. A 230 kg dry, foil-covered statue why?   


v. A 230 kg limestone statue why?

A block of mass m= 5.00-kg is moving to the right with a speed of v= 2.00 m/son a horizontal,frictionless surface. The block encounters a relaxed(that is, neither compressed nor extended)spring with spring constant k= 2,000.00 N/m.

a.What is the kinetic energy of the block before hitting the spring?

b.What is the kinetic energy of the block when the spring is at maximum compression?

c.How much energy is stored in the spring at maximum compression?

d.How far does the spring compress at its maximum compression?

e.If the spring converts its stored energy completely into motion of the block, what is the speedof the blockafter release from the spring?

f.(For this part of the problem,the surface is not frictionless) Suppose the speed of the block after release from the spring is 1.5 m/s to the left, how much work (sign and magnitude) was done by non-conservative forces between the time when the initial velocity is 2.00 m/s and the time when the velocity = -1.50 m/s?