20#15

Given the following half-reactions and associated standard reduction potentials:
AuBr−4(aq)+3e−→Au(s)+4Br−(aq)
E∘red=−0.858V
Eu3+(aq)+e−→Eu2+(aq)
E∘red=−0.43V
IO−(aq)+H2O(l)+2e−→I−(aq)+2OH−(aq)
E∘red=+0.49V
Sn2+(aq)+2e−→Sn(s)
E∘red=−0.14V

a) Write the cell reaction for the combination of these half-cell reactions that leads to the largest positive cell emf.

b) Calculate the value of this emf.

E∘max = _____ V

c) Write the cell reaction for the combination of half-cell reactions that leads to the smallest positive cell emf.

d) Calculate the value of this emf.

E∘min = _____ V

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

A novelty collision device known as the executive toy consists of five identical metal balls. When one ball swings in, after multiple collisions, one ball swings out at the other end of the row of balls. When two balls swing in, two swing out; when three swing in, three swing out, and so on-always the same number out as in. Suppose that one ball, with mass m, swing in and collide with the next ball with a velocity v. Why don’t two ball swing out at the other end with a velocity of v/2? Clearly establish the reasoning and physical principles to receive full credit.

Can someone explain to me what laws are being used here and how it relates to the question? Thank you.

Ahmed owns Ahmed Manufacturing LLC based in Muscat. In deciding on several important business-related decisions, he has to deal with the following independent scenarios/statements: (i) All future costs are relevant in decision making (ii) A sunk cost is a cost that is yet to be incurred but that can be avoided at least in part depending on the action a manager takes. (iii) A cost that will be incurred regardless of Ahmed’s action is relevant to his decision. (iv) In a decision to drop a segment, the opportunity cost of the space occupied by the segment would be zero. (v) Common fixed overhead that will continue if the special offer is not accepted is relevant to Ahmed’s decision. For each of the scenario/statement (i) to (v) above, STATE your agreement OR disagreement and provide appropriate EXPLANATION(S) / JUSTIFICATION(S).

Consider an RLC circuit with resistance 20Ω20Ω  , inductance 0.05H0.05H , capacitance 2500μF2500μF , and an impressed voltage, provided by an alternating current generator, with V=50V,120HzV=50V,120Hz. At t=0t=0 V=0V,Q=2C,I=1AV=0V,Q=2C,I=1A.

a. Complete the ODE below in terms of the charge in the circuit Q(t)Q(t)

   _____Q''+ _____Q' + _____Q = ______

b. Solve the ODE and complete the equation for the charge Q(t)=Q(t)=   

c. Upload a file with your work for part b and a graph of the current I(t)


d. Write a short essay to Interpret the graph of the current in the context of the RLC circuit scenario. Explain the whole graph (initial conditions, overall pattern, end behavior) in the context provided.

Two blocks in a system (b1 & b2) collide inelastically where b1 has a velocity (v) and a small mass (m) and b2 is stationary with a large mass (M). b2 can absorb some of the collision similar to a spring that does not recoil with a stiffness of (k). When the blocks collide they will stick together. The plane that the blocks are moving on is horizontal and frictionless.

1)Find the change in internal energy (delta U)

2)If all of the energy change is stored as potential energy of a spring that cannot recoil find the distance of compression that the spring undergoes in terms of v, m and k.

3)Now assume that during the collision the surface is hot. Shortly after the collision the blocks reach thermal equilibrium. Find (delta U) a few seconds after the collision

In a direct formic acid fuel cell, formic acid (HCOOH) is oxidised into carbon dioxide and water over an alloy nanoparticle catalyst. The standard reduction potential for O2 is +1.23 V and for the reduction of CO2 to HCOOH is -0.25 V. (a) Write down balanced equations for each half-cell reaction and the overall cell reaction. Calculate the standard potential of the cell. (b) Under operating conditions, the concentration of HCOOH is 5.0 mol dm-3, and the pressures of O2 and CO2 are 3.4 and 1.9 bar respectively. Assuming ideal behaviour, calculate the operating voltage of the cell at 298 K. (c) If the entropy change for the reaction is +34.2 J K-1 mol-1, calculate the operating voltage of the cell at 353 K. Comment on the implications of your answers for the chosen operating conditions.

A parallel plate capacitor with adjustible plate separation d and adjustible area A is connected to a battery. The capacitor is fully charged to Q Coulombs and a voltage of V Volts. (C is the capacitance and U is the stored energy.) Give all correct answers concerning a parallel-plate capacitor charged by a battery (e.g. B, AC, CDF).

A) After being disconnected from the battery, increasing the area A will increase C.
B) With the capacitor connected to the battery, increasing the area A will decrease U.
C) With the capacitor connected to the battery, increasing d increases U.
D) With the capacitor connected to the battery, increasing the area A will increase Q.
E) After being disconnected from the battery, increasing d increases V.
F) With the capacitor connected to the battery, increasing d increases C.

Let the market for cigarettes be characterized by the following information: Qd = 70 – 5P [Demand] Qs = 3P – 10 [Supply] Suppose the government imposes a sales tax of $2.50 per unit. Answer questions

(i) through (v) below: i) [10 points] Calculate the magnitude of the consumer surplus and producer surplus in the pre-tax equilibrium.

ii) [10 points] Calculate the tax revenue in the post-tax equilibrium.

iii) [10 points] Calculate the change in consumer surplus due to the sales tax.

iv) [10 points] Calculate the change in producer surplus due to the sales tax.

v) [10 points] Calculate the Dead-Weight-Loss due to the sales tax.

Be very complete in every answer with explaining Dead-Weight-Loss with steps with every question show the complete work and it should be perfect