1. Explain what is work (physics term)? What is kinetic energy? The relationship between the work

done by the net force on the object and kinetic energy of object.

2. How do you know the work-energy theorem is true? (hint: describe clearly how it works in yourexperiment or in real life)

So Gerard 't Hooft has a brand new paper (thanks to Mitchell Porter for making me aware of it) so this is somewhat of a expansion to the question I posed on this site a month or so ago regarding 't Hoofts work.

Now he has taken it quite a big step further: http://arxiv.org/abs/1207.3612

Does anyone here consider the ideas put forth in this paper plausible? And if not, could you explain exactly why not?

1) a) A charge of +5.00 nC is placed at the origin, and another charge of -3.00 nC is

placed 2.5 cm west of origin, what is the electric potential at 3 cm east from origin?

b) Repeat a) at distance 5 cm north of origin.

c) Find the work done to bring another charge of -5.00 nC from infinity to the point at 3 cm east from origin.

with the same three capacitors in parallel. How is this different than the result in series?

2) Three resistors of 25.00 ?, 17.00 ? and 13.00 ? are connected in series to a source with a potential difference of 3.00 V.

a) What is the equivalent resistance?

b) What is the the current in each resistor, and what is the potential difference across each resistor?

c) What is the power in each capacitor?

with the the same resistors in parallel. How is this different than the result in series?

A circus act involves launching a human being from a cannon resting on the floor. The human has a 50 kg mass and is launched at a speed of 12 m/s, in a direction 30° up from the horizontal. The cannon has a mass of 110 kg. (a) Considering the system as cannon + human, state why the x-component of the momentum is conserved. (b) Find the recoil speed of the cannon. (c) It would be dangerous to use explosives, so the performer is actually launched from a loaded spring inside the barrel, compressed 1.7 m from its equilibrium position. Find the spring constant needed to achieve the launch + recoil. (d) You will note that the y-component of the net momentum is NOT conserved, since the performer flies up in the air. Why is the x-component conserved but the y-component not?

A cylinder of radius 2.59 cm and a spherical shell of radius 6.72 cm are rolling without slipping along the same floor. The two objects have the same mass. If they are to have the same total kinetic energy, what should the ratio of the cylinder\'s angular speed to the spherical shell\'s angular speed be?

A 3.05-kg ball of clay is thrown downward from a height of 2.75 m with a speed of 5.01 m/s onto a spring with k = 1750 N/m. The clay compresses the spring a certain maximum amount before momentarily stopping. What is the total work done on the clay during the spring's compression? Also, how would one go about solving for that?

A hollow aluminum cylinder 23.5 cm deep has an internal capacity of 2.000 L at 17.0°C. It is completely filled with turpentine at 17.0°C. The turpentine and the aluminum cylinder are then slowly warmed together to 75.0°C. (The average linear expansion coefficient for aluminum is 24 ✕ 10−6°C−1, and the average volume expansion coefficient for turpentine is 9.0 ✕ 10−4°C−1.)

(a) How much turpentine overflows? cm3

(b) What is the volume of turpentine remaining in the cylinder at 75.0°C? (Give your answer to at least four significant figures.) L

(c) If the combination with this amount of turpentine is then cooled back to 17.0°C, how far below the cylinder's rim does the turpentine's surface recede?

1.Explain in a short paragraph what a heat engine is and what it does. Make sure your explanation includes: (a) what is the purpose of a heat engine, (b) what does a heat engine need to achieve that purpose, and (c) what limits how well a heat engine can achieve that purpose ("efficiency")?

2.The idea that evaporation is a cooling process is a familiar and intuitive one. What sounds counter-intuitive at first is this claim: "Boiling is a cooling process" (but hopefully the first two videos above have convinced you of the veracity of this claim). Explain how boiling is a cooling process. Make sure your explanation refers to latent heat (or "latent heat of vaporization", to be specific). What is the key difference between evaporation and boiling?

Consider a rocket that burns steadily. The higher pressure in the combustion chamber, the faster the propellant burns. Why is this? The relationship is such that the higher the pressure, the closer the gaseous flame is to the surface and the more effectively it can transfer heat back to the surface thereby gasifying the propellant quicker. The rate of gas generation, ?_? , can be described by the equation: ?_?=?_1 ?^?, where P is the pressure, and C1 and n are the constants for a given propellant with given exposed surface area.

The hot gas leaving the rocket must pass through the throat of the exhaust nozzle at sonic velocity.

▪The higher the pressure, the greater the density of this gas and the greater the rate of mass flow at sonic velocity. (The speed of sound in a gas is independent of pressure.) Accordingly, the rate of gas escape, ??r_e , is described by the equation: ??=?2?r_e=C_2 P where C2 is a constant, dependent on cross section area of the nozzle throat and on the velocity of sound in the combustion products.

▪What is the steady operating pressure of a solid-propellant rocket for the given values of the constants C1 , C2, and n? What values of n keep it stable?

PLEASE WRITE CLEARLY AND EXPLAIN WHY IS THE ANSWER THE WAY IT IS PLEASE THANK YOU

A 1.56 kg block is held in equilibrium on an incline of angle q = 53.0o by a horizontal force, F, applied in the direction shown in the figure below.

When traveling through mountains, most highways periodically have emergency escape ramps to allow large, heavy vehicles to stop safely, even when their brakes are not working properly. One such escape ramp is angled 13 ∘ above the horizontal. The brakes on one large truck (mass 1.4×10⁴ kg ) fail when driving at a speed of 80 miles per hour (35.75 m/s), and the driver makes use of the escape ramp.

Part A: What is the minimum length of ramp necessary for this truck to come to a stop? Assume negligible friction and air resistance forces.

Part B: If instead dissipative forces (friction and air resistance) provide a constant force of 60,000N parallel to the ramp, what is the minimum length of ramp necessary for this truck to come to a stop?

my answer for part A is 290 m, but I am unsure how to get the answer for part B. please help

The 2015 supermoon eclipse of the moon took place when the moon was at perigee.

(a) How much larger (as per cent) is the angular radius of the moon at perigee compared to apogee?

(b) The moon is drifting away from the Earth at a rate of 4 cm per year. How long will it take until we no longer see any total Solar eclipses at perigee? You may assume that the semi-major axis of the Earth-Sun system does not change over this period

Question 1:

A uniform disk with mass 35.4 kg and radius 0.240 m is pivoted at its center about a horizontal, frictionless axle that is stationary. The disk is initially at rest, and then a constant force 27.5 N is applied tangent to the rim of the disk.

Part A

What is the magnitude v of the tangential velocity of a point on the rim of the disk after the disk has turned through 0.260 revolution?

Part B

What is the magnitude a of the resultant acceleration of a point on the rim of the disk after the disk has turned through 0.260 revolution?

_____________________________

Question 2:

A woman with a mass of 55.0 kg is standing on the rim of a large disk that is rotating at an angular velocity of 0.540 rev/s about an axis through its center. The disk has a mass of 108 kg and a radius of 4.50 m .

Part A

Calculate the magnitude of the total angular momentum of the woman-plus-disk system. (Assume that you can treat the woman as a point.)

Please: Answer all of below &Clear and briefly answer & Clearly identifiable handwriting or computer typing

Please give arguments about what determines the width of a ferromagnetic domain
wall?

5 moles of a monoatomic ideal gas are contained adiabatically at 50 atm pressure and 300 K. The pressure is suddenly released to 10 atm, and the undergoes an irreversible expansion during which it performs 4000 joules of work. Show to the final temperature of the gas after the irreversible expansion is greater than that which the would attain if the expansion from 50 to 10 atm had been conducted reversibly. Calculate the entropy product as a result of the irreversible expansion. The constant-volume molar heat capacity of the Gas is C_v has a volume of 1.5 R.