A metal surface is susceptible to a photoelectric threshold frequency of 8.529*10>14Hz. Will the monochromatic UV light sources of wavelengths 283 nm, 342 nm, and 363 nm be able to eject photoelectrons from the metal. If so what is the speed of the fastest electron ejected?

An electron in a TV camera tube is moving at 7.20×10⁶ m/s in a magnetic field of strength 59 mT. Without knowing the direction of the field, what can you say about the greatest and least magnitude of the force acting on the electron due to the field? Maximum force?

Minimum force?

At one point the acceleration of the electron is 6.327×10¹⁶ m/s². What is the angle between the electron velocity and the magnetic field? (deg)

Solid-state physics

a, How many electrons are needed to fill all states in a band?

b, What is the meaning of the Fermi energy?

c, What is the Fermi surface of a metal?

Please explain thoroughly

Chemical reactions are often described using a three state model:

Reactants→Transition State→ProductsReactants→Transition State→Products

In most cases the energy of the transition state is much higher than the energy of the reactant state. This means that the reaction cannot proceed until there is a random thermal fluctuation large enough to `kick' the reactant molecule(s) up to the transition state energy. Say we have a reaction in which the transition state is 9.0×10⁻²⁰ J above the reactant state.

a.) Calculate the ratio of the probability the system is in the transition state to the probability that it is in the reactant state (P_TS/P_R) at 37 C.

P_TS/P_R = (7.3 x 10^-10 is correct)

b.) Use your answer above to estimate the time it takes for the reaction to occur spontaneously at 37 C. Assume that the system samples a new microstate every nanosecond (10⁻⁹ s).

[Hint: If you throw a 6-sided die, what is the probability you will get a 3? How many times would you expect to have to throw the die to get a 3? Using similar logic, use your answer in the first part to tell you how many times the system has to try before it gets a fluctuation that is big enough.]

time: (2.1 x 10^-8 s is incorrect)

c.) One way to speed up the reaction is to heat the system. If the temperature is increased to 1000 K, how long does it take for the reaction to occur?

time: (.009325 s is incorrect)

d.) In biological systems it is not feasible to accelerate reactions by heating them to 1000 K. Instead, the reactions rely on enzymes that catalyze reactions by lowering the energy of the transition state. If catalyzed reaction has a transition state energy 2.0×10⁻²⁰ J, what is the approximate reaction time? Use a temperature 37 C.

time: (6.52 x 10^-9 s is incorrect)

e.) Finally, estimate the uncatalyzed reaction time if the transition state is not a unique microstate, but actually an ensemble of 100 microstates. Use a temperature 37 C.

time: (4.675 x 10^-9 s is incorrect)

derive the Jarzynski equality from the Crooks fluctuation theorem (CFT) and the non-equilibrium partition identity.

A particle of mass M moves along a straight line with initial speed vi. A force of magnitude Fpushes the particle a distance D along the direction of its motion.

A) Find vf, the final speed of the particle after it has traveled a distance D. Express the final speed in terms of vi, M, F, and D.

B) By what multiplicative factor RK does the initial kinetic energy increase, and by what multiplicative factor RW does the work done by the force increase (with respect to the case when the particle had a mass M)? If one of the quantities doubles, for instance, it would increase by a factor of 2. If a quantity stays the same, then the multiplicative factor would be 1. You should enter the two factors separated by a comma.

C) By what factor RK does the initial kinetic energy increase (with respect to the first situation, with mass M and speed vi), and by what factor RW does the work done by the force increase?

A wedge of mass M rests on a rough horizontal surface with coefficient of friction µ. The face of the wedge is a smooth plane inclined at an angle θ to the horizontal. A mass A hangs from a light string which passes over a smooth peg at the upper end of the wedge and attaches to a mass B which slides without friction on the face of the wedge.

(i) Find the accelerations for the masses A and B, and the tension in the string when µ is very large.
(ii) Find the smallest coefficient of friction for which the wedge will remain at rest.

A thin film having an index of refraction of 1.50 is surrounded by air. It is illuminated normally by white light. Analysis of the reflected light shows that the wavelengths 360, 450, and 600 nm are the only missing wavelengths in the visible portion of the spectrum. That is, for those wavelengths, there is destructive interference.

(a) What is the thickness of the film?
nm

(b) What wavelengths in the visible portion of the spectrum are brightest in the reflected interference pattern? (Enter your answers from smallest to largest.)

(c) If this film were resting on glass that has an index of refraction of 1.60, what wavelengths in the visible spectrum would be missing from the reflected light? (Enter your answers from smallest to largest.)
....... nm
....... nm
....... nm

Derive an expression for the total number of stars between masses M1 and M2, where M1 < M2.

Can the Salpeter IMF extend to arbitrarily low mass stars? Justify your answer quantitatively

Derive an expression for the total mass in stars formed with masses between M1 and M2, where M1 < M2.

Relation among material buckling, geometry buckling and multiplication factor.

A violin string 20.0 cm long with mass 4.8 g and tension 48 N, fixed at both ends, oscillates in its n=2 mode. What is the wavelength in air of the sound emitted by this vibrating string? ( The speed of the sound in air is 343 m/s.)

The answer is 1.534 m, not sure how to find it.

Explain the physics meaning of material buckling and geometry buckling.

Errors are essential in physics Labs when measuring physical quantities. Discuss the most important techniques that we must follow in order to minimize such problems? Support your answer by example.

The area enclosed by the wire loop in the figure below is reduced from 31 cm2 to 12 cm2 in a time interval of 0.11 s. The magnitude of the magnetic field is 0.53 T. Find the emf induced in the wire.