In the interval between the freezing point (ice point) of water and 700.0deg-C, a platinum resistance thermometer is to be used for interpolating temperatures from 0 °C to the melting point of zinc, 692.666 K. The temperature, in Celcius or Centigrade, is given by a formula for the variation of the resistance of the thermometer with temperature: R = R,o(1 + A Tc + B Tc^2). Ro, A, and B are constants determined by measurements at the ice point, the steam point, and the melting point of zinc. If R equals 12.88350 ohms at the ice point, 88.31639 ohms at the steam point, and 304.28989 ohms at zinc's melting point, find Ro. What is A? What is B?

Modern Physics

A trip is planned to to visit the Alpha Centauri star system 4.3 light years away. Provisions are put in place to allow a trip of 16 years' total duration. How fast must the spacecraft travel if the provisions are to last? Neglect the period of acceleration, turnaround, and visiting times. Express your answer as a multiple of c.

I did the following:

I cut an irregular sheet out of a piece of paper.
I tied the string with a washer at one end to the push pin.
I punched holes in three spot at different "corners" of the paper.
I hung the paper with the push pin from the first hole and let the washer hang down.
I traced the plumb line with a pencil.
I repeated steps 4 and 5 for the other holes.

a) If you cut an irregular shape out of paper and hang it from a thumbtakc it balances around that point it is hung from. If you draw a line straight down the paper from the thumbtack, how is the mass distributed on either side of the line you draw when it is hanging like this?

b) What does the point where the three lines intersect represent? Explain why this method works.

c) Is the third line necessary to find the center of mass? Why or why not?

Two rods, one made of brass and the other made of copper, are joined end to end. The length of the brass section is 0.220m and the length of the copper section is 0.780m . Each segment has cross-sectional area 5.10?10^?3m2 . The free end of the brass segment is in boiling water and the free end of the copper segment is in an ice and water mixture, in both cases under normal atmospheric pressure. The sides of the rods are insulated so there is no heat loss to the surroundings.

1)What is the temperature of the point where the brass and copper segments are joined?

2)What mass of ice is melted in 6.90

min by the heat conducted by the composite rod?

a) The electric potential at a position located a distance of 21.9 mm from a positive point charge of 8.20×10^-9C and 13.9 mm from a second point charge is 1.26 kV. Calculate the value of the second charge.
_____???

b) The potential difference between two parallel conducting plates in vacuum is 175 V. An alpha particle with mass of 6.50×10^-27 kg and charge of 3.20×10^-19 C is released from rest near the positive plate. What is the kinetic energy of the alpha particle when it reaches the other plate? The distance between the plates is 29.0 cm.
_____???

c) A positive charge of 4.80 μC is fixed in place. From a distance of 4.00 cm a particle of mass 5.20 g and charge +3.80 μC is fired with an initial speed of 76.0 m/s directly toward the fixed charge. How close to the fixed charge does the particle get before it comes to rest and starts traveling away?
_____???

d) A charge Q₁ = 1.23 μC is at rest and is located 2.10 cm away from another fixed charge Q₂ = 1.75 μC. The first charge is then released. Calculate the kinetic energy of charge Q₁ when it is 5.50 cm away from charge Q₂.
_____???

e) To recharge a 15.0 V battery, a battery charger must move 3.00×10⁵ C of charge from the negative terminal to the positive terminal. How much work is done by the battery charger?
_____???

Please help with this asap w/ work! Thanks!

Asteroids can be classified into two broad groups based on their composition and location: carbon-rich asteroids dominate the outer part of the asteroid belt, whereas metal-rich asteroids dominate the inner part of the belt. Analysis of the fragment we have discussed in this project reveals that it contains nearly equal amounts of metals and carbon. Can you conclude that the original whole asteroid had a similar composition? Can you conclude with a high degree of confidence that the asteroid originated in the middle regions of the asteroid belt? Explain your reasoning. If you would need more data from the asteroid analysis, what would you like to see?

Provide TWO specific strategies that an equipment designer could employ to reduce heating of

the temperature-sensitive components and explain how physics concepts are applied in each

strategy.

A textbook of mass 2.08 kg rests on a frictionless, horizontal surface. A cord attached to the book passes over a pulley whose diameter is 0.160 m , to a hanging book with mass 3.10 kg . The system is released from rest, and the books are observed to move a distance 1.30 m over a time interval of 0.770 s . What is the moment of inertia of the pulley about its rotation axis?

Naive reasoning suggests that a string theory vacuum with cosmological constant Lambda1 is always unstable as long as there is a string theory vacuum with cosmological constant Lambda2 < Lambda1 since the later is a state with lower energy density. If it's true, there should be very few stable vacua since these would be the vacua with the lowest possible cosmological constant. These vacua would probably have a Planckian-size cosmological constant and therefore be highly non-classical.

However, I suspect there is something wrong with this line of reasoning. Probably I am thoroughly confused about something.

Also, how to compare stability of vacua with different number of large dimensions? Comparing cosmological constants doesn't feel to make sense.

Use the Conservation of Angular Momentum to explain why a tail rotor is necessary to stabilize the flight of a helicopter.

Find the minimum aperture diameter of a camera that can resolve detail on the ground the size of a person (2.1 m) from an SR-71 Blackbird airplane flying at an altitude of 23 km. (Assume light with a wavelength of 470 nm.)

1. What is the magnitude of the average gravitational force between the Sun and Mercury?
2. What is the magnitude of the average gravitational force between the Sun and Mercury if the orbital radius of Mercury was doubled?

(you will have to look up Newton's Universal Law of Gravitation and some values of mass and distance) and please list them with the solution.

Please answer in scientific notation and round to three significant figures.

Who pushed the Montreal Protocol on Substance that Deplete the Ozone into prominence?

During which phase(s) of the Moon is it possible to observe the Moon rising after Sunset but before Midnight