1. You and a friend are riding the subway, and sit at opposite ends of the car. You both count down from five, and then clap simultaneously, just as the train passes through a station. (It's an express train, so you don't slow down and stop at the station.)

   According to the predictions of special relativity, what would an observer on the subway platform observe as you passed through the station?

   		Your claps would not be simultaneous. One would occur before the other.
   		Your claps would occur at the same time.
   		Your claps would occur at the same time, but time would speed up for you, so they would occur more quickly.

2. Which of the following statements are true regarding light clocks and time dilation? (Select all that apply.)

   		If two observers are in relative motion, they will disagree about whose light clock is running more slowly.
   		Two light clocks are synchronized. They will remain synchronized even if one moves, because motion is relative.
   		A moving light clock ticks more quickly than a stationary one.
   		Because light clocks are just a way to measure time, and any clock could be synchronized with a light clock, the light clock thought experiment actually tells us that time itself slows down for moving objects.
   		A moving light clock ticks more slowly than a stationary one.

3. If I am stationary, and I see you move (from my point of view) at a speed of 25% of the speed of light, which of the following statements is true regarding how I will observe time passing for you?

   		I will observe time moving more slowly for you than for me.
   		I will observe time moving more quickly for you than for me.
   		Time will pass more slowly for you and for me, but I will not notice it because I am stationary.
   		I will measure no difference between the rate at which time passes for you and the rate that it passes for me.

Name three types of ways corruption of science can occur.
Given a scenario/example to support each way.

A 0.50-μF and a 1.4-μF capacitor (C1 and C2, respectively) are connected in series to a 22-V battery.

Part A: Calculate the potential difference across each capacitor.

Part B: Calculate the charge on each capacitor.

Part C: Calculate the potential difference across each capacitor assuming the two capacitors are in parallel.

Part D: Calculate the charge on each capacitor assuming the two capacitors are in parallel.

. A leading manufacturer of household appliances is proposing a self-cleaning oven design that involves use of a composite window separating the oven cavity from the room air. The composite is to consist of two high-temperature plastics (A and B) of thickness LA = 2LB and thermal conductivities kA = 0.15 W/mK and kB = 0.08 W/mK. During the self-cleaning process, the oven wall and inside air temperatures, Tw and Ta are 400 ºC, while the room air temperature is 25 ºC. The inside convection and radiation heat transfer coefficients hi and hr as well as the outside convection coefficient ho, are each 25 W/m2K.

(a) Define and sketch the system and identify heat entering and leaving the system on the sketch.

(b) Write the conservation of energy equation (or energy balance) for this system.

(c) Construct a thermal resistance circuit for the system defined in part (a).

(d) Write an expression for the total resistances entering the system.

(e) What is the minimum window thickness, L = LA + LB, needed to ensure a temperature that is 50 ºC or less at the outer surface of the window? This temperature must not be exceeded for safety reasons

A parallel-plate capacitor has square plates that are 8.20 cm on each side and 4.80 mm apart. The space between the plates is completely filled with two square slabs of dielectric, each 8.20 cm on a side and 2.40 mm thick. One slab is Pyrex glass and the other slab is polystyrene. If the potential difference between the plates is 88.0 V, find how much electrical energy (in nJ) can be stored in this capacitor.

1.Two point charges, q₁= +6 nC and q₂= +5 nC, are located on the x-axis at x= 0 and x=5.00 m. What is the electric field at point x=1.27 m? I got 33.4801 is ths correct?

2.Two point charges, q₁= +2 nC and q₂= -4 nC, are located on the x-axis at x= 0 and x=5.00 m. What is the electric field at point x=5 m? I got is this correct .7199?

3.Two point charges, q₁= +4 nC and q₂= -14 nC, are located on the x-axis at x= 0 and x=8 m. What is the distance of ZERO electric field from the positive charge?

A small diamond of mass 15.9 g drops from a swimmer's earring and falls through the water, reaching a terminal velocity of 1.9 m/s.

(a) Assuming the frictional force on the diamond obeys f = −bv, what is b (in kg/s)? (Round your answer to at least four decimal places.)

(b) How far (in m) does the diamond fall before it reaches 90 percent of its terminal speed?

A skydiver of mass 82.0 kg jumps from a slow-moving aircraft and reaches a terminal speed of 49.9 m/s.

(a) What is her acceleration when her speed is 30.0 m/s?

(b) What is the drag force on the skydiver when her speed is 49.9 m/s?

(c) What is the drag force on the skydiver when her speed is 30.0 m/s?

A coil of inductance 120 mH and unknown resistance and a 1.0 μF capacitor are connected in series with an alternating emf of frequency 950 Hz. If the phase constant between the applied voltage and the current is 78°, what is the resistance of the coil?

Identify a practical example of Newton’s law of acceleration. Explain how the example illustrates the law.

Please show work. Thank you!!

Question 3:

1. ) Air contains approximately 80% N₂ and 20% O₂.
   1. At STP, what is the rms speed of O₂ molecules in air?
   2. At STP, what is the average KE of an O₂ molecule?
   3. At STP, what is the rms speed of N₂ molecules?
   4. If we don’t distinguish between N₂ and O₂, what would be the average rms speed?

1. Actual question:) Now consider the same situation as in problem (3) but the 50 cm long rod is half aluminum and half copper. The aluminum end is in boiling water.

1. What would be the steady temperature of the Al-Cu junction?
2. How much ice will the rod melt in 20 minutes.

Firstly, I wasn't sure exactly where to put this. It's a typesetting query but the scope is greater than TEX; however it's specific also to physics and even more specific to this site.

I've recently been reading a style guide for scientific publications (based on ISO 31-11), however there was no mention of quantum mechanical operators. I've seen them written a few ways and was wondering if there was a decision handed down from "up above" that any particular way is best.

H -- I see this most commonly but I suspect it's mostly due to (mild) laziness to not distinguish it from a variable.
H^ -- This is nicer to me because it makes the distinction between operator and variable. From what I understand of the ISO the italic means it's subject to change, which is true of the form of an operator, but not really its meaning? So I'm not totally sure if that's appropriate here.
H -- Roman lettering is used for functions e.g. sinx, erf(x), and even the differential operator (as in ddx) so this seems to me like the most suitable category to put operators in.
H^ -- Probably the least ambiguous but may also be redundant.

Which would be the best to use? Am I being too pedantic?

In nature, is total energy always conserved (yes or no)? Why?

A 10-cm-long thin glass rod uniformly charged to 15.0 nC and a 10-cm-long thin plastic rod uniformly charged to - 15.0 nC are placed side by side, 4.40 cm apart. What are the electric field strengths E1 to E3 at distances 1.0 cm, 2.0 cm, and 3.0 cm from the glass rod along the line connecting the midpoints of the two rods?

Specify the electric field strength E1

Specify the electric field strength E2

Specify the electric field strength E3

Expand 1.00 mol of a monatomic gas, initially at 3.60 kPa and 313 K, from initial volume V_i = 0.723 m³ to final volume V_f = 2.70 m³. At any instant during the expansion, the pressure p and volume V of the gas are related by p = 3.60 exp[(V_i - V)/a], with p in kilopascals, V_i and V are in cubic meters, and a = 2.10 m³. What are the final (a) pressure and (b)temperature of the gas? (c) How much work is done by the gas during the expansion? (d) What is the change in entropy of the gas for the expansion? (Hint: Use two simple reversible processes to find the entropy change.)