Describe the development of the quantum model of electromagnetic radiation

A snake of proper length 100 cm is moving at speed v = 0.6c to the right across the table. A mischievous boy, wishing to tease the snake, holds two hatchets 100 cm apart and plans to bounce them simultaneously on the table so that the left hatchet lands immediately behind the snake’s tail 1 .

The boy argues as follows: “The snake is moving with v = 0.6c, therefore, its length measured in my frame is 100cm γ = 80 cm. This implies that the right hatchet will fall 20 cm in front of the snake, and the snake will be unharmed”. On the other hand, the snake argues “the hatchets are approaching me at 0.6c, and the distance between them is 80 cm. Since I am 100 cm long, I will be cut in pieces when they fall” (it’s a very smart snake).

Use Lorentz transformation to resolve this apparent paradox. In other words, resolve it quantitatively, not just with a qualitative argument about non-simultaneity.

Please show work quantitatively, thanks!

Estimate the thickness of a CdSe quantum dot film needed to absorb 90% of the incident light.

Explain the apparent contradiction between the Principle of Local Equivalence and the principle of mass independence established by Galileo. Then resolve this in terms of Einstein's vectorial acceleration.

1. The following questions relate to the following scenario.

A student is listing possible factors that determine the change in the kinetic energy of objects. She has collected data in the following experimental setup:

Two blocks with different masses are free to slide on a very, very smooth table between two parallel lines. An air blower pushes each block horizontally, exerting the same constant force. Both blocks start from rest and cover the same distance on their track under the action of the air blower. The experimental data collected by the groups support the claim that the final kinetic energies of the two blocks are equal.

Of the following explanations, which is the most correct and complete causal account of the kinetic energies of the two blocks being equal?

Group of answer choices

-The two blocks have equal final kinetic energies because when there is negligible friction, mechanical energy stays constant.

-The two blocks have equal final kinetic energies because the blower transfers to each of them equal amounts of energy per meter.

-The two blocks have equal final kinetic energies because the blower transfers to each of them equal amounts of energy per second.

-The two blocks have equal final kinetic energies because the higher final speed of the lighter block compensates for its smaller mass.

You throw a rock at time t=2 s at an angle of theta=-2 degrees with a speed of v=24 m/s from a high cliff. Calculate the speed of the ball at the time t=11 s. Use g=10 m/s/s.

The Nile River runs from east to west. Assume the water in the Nile is electrically neutral while still conducting, and that the ions (both positive and negative in equal concentration) are carried with the flow of the water. What would the electric potential of the north side of the river be in comparision to the southern side due to the lorentz force on the ions. Remember that the magnetic field of the earth has northern and southern components.

sinusoidal wave of angular frequency 1205 rad/s and amplitude 3.20 mm is sent along a cord with linear density 2.10 g/m and tension 1233 N. (a) What is the average rate at which energy is transported by the wave to the opposite end of the cord? (b) If, simultaneously, an identical wave travels along an adjacent, identical cord, what is the total average rate at which energy is transported to the opposite ends of the two cords by the waves? If, instead, those two waves are sent along the same cord simultaneously, what is the total average rate at which they transport energy when their phase difference is (c) 0, (d) 0.6? rad, and (e)? rad?

I figured everything out except part d

A bullet with a mass m b = 11.5 g is fired into a block of wood at velocity v b = 265 m/s. The block is attached to a spring that has a spring constant k of 205 N/m. The block and bullet continue to move, compressing the spring by 35.0 cm before the whole system momentarily comes to a stop. Assuming that the surface on which the block is resting is frictionless, determine the mass of the wooden block. From left to right, a bullet of mass m subscript b has a velocity of v subscript b with a velocity vector pointing directly to the right. The vector points toward a block that is attached on its right face to a spring of force constant k. The other end of the spring is attached to a fixed, vertical surface. mass of wooden block: kg

3. (a) An outfielder fields a baseball 280 ft away from home plate and throws it directly to the catcher with an initial velocity of 100 ft/s. Assume that the velocity v(t) of the ball after t seconds satisfies the di↵erential equation dv dt = 1 10 v because of air resistance. How long does it take for the ball to reach home plate? (Ignore any vertical motion of the ball.) (Instructor’s hint: Recall that a di↵erential equation of the form dv/dt = kv has solution v(t) = v(0)ekt.) (b) The manager of the team wonders whether the ball will reach home plate sooner if it is relayed by an infielder. The shortstop can position himself directly between the outfielder and home plate, catch the ball thrown by the infielder, turn, and throw the ball to the catcher with an initial velocity of 105 ft/s. The manager clocks the relay time of the shortstop (catching, turning, throwing) at half a second. How far from home plate should the shortstop position himself to minimize the total time for the ball to reach home plate? Should the manager encourage a direct throw or a relayed throw? What if the shortstop can throw at 115 ft/s? (Instructor’s hint: Let x represent the distance between the shortstop and home plate, then find an expression for the time it takes that ball to reach home plate as a function of x. It is also helpful to use a variable w to represent the shortstop’s throwing velocity, since you can then substitute the di↵erent given values in place of w.) (c) For what throwing velocity of the shortstop does a relayed throw take the same time as a direct throw

Please answer part b

A point charge q2 = -1.9 μC is fixed at the origin of a co-ordinate system as shown. Another point charge q1 = 4.5 μC is is initially located at point P, a distance d1 = 6.6 cm from the origin along the x-axis

1) What is ΔPE, the change in potenial energy of charge q₁ when it is moved from point P to point R, located a distance d₂ = 2.6 cm from the origin along the x-axis as shown?

2) The charge q2 is now replaced by two charges q3 and q4 which each have a magnitude of -0.95 μC, half of that of q2. The charges are located a distance a = 1.6 cm from the origin along the y-axis as shown. What is ΔPE, the change in potential energy now if charge q1 is moved from point P to point R?

3)What is the potential energy of the system composed of the three charges q1, q3, and q4, when q1 is at point R? Define the potential energy to be zero at infinity.

4)The charge q4 is now replaced by charge q5 which has the same magnitude, but opposite sign from q4 (i.e., q5 = 0.95 μC). What is the new value for the potential energy of the system?

5)Charges q3 and q5 are now replaced by two charges, q2 and q6, having equal magnitude and sign (-1.9μC). Charge q2 is located at the origin and charge q6 is located a distance d = d1 + d2 = 9.2cm from the origin as shown. What is ΔPE, the change in potential energy now if charge q1 is moved from point P to point R?

a) An electron with 10.0 eV kinetic energy hits a 10.1 eV potential energy barrier. Calculate the penetration depth.

b) A 10.0 eV proton encountering a 10.1 eV potential energy barrier has a much smaller penetration depth than the value calculated in (a). Why?

c) Give the classical penetration depth for a 10.0 eV particle hitting a 10.1 eV barrier.

1.a)What is corona discharge?

b)Why engineers avoid sharp extensions in high voltage wires?

c)What is a capacitor and capacitance?

d)What is capacitor good for?