7. A very long straight wire carries a 12-A current eastward and a second very long straight wire, 42 cm below the first wire, carries a 14-A current westward. The wires are parallel to each other. Calculate the total magnetic field halfway between the wires. Include the direction.

How is energy an eigenvalue? Do the math.

Kinetic energy= T= 1/2 mv^2 = p^2 / 2m = h^2 / 2m Lambda^2

1. A 200 g aluminum calorimeter can contain 500 g of water at 20 C. A 100 g piece of ice cooled to -20 C is placed in the calorimeter.

1. Find the final temperature of the system, assuming no heat losses. (Assume that the specific heat of ice is 2.0 kJ/kg K)
2. A second 200 g piece of ice at -20 C is added. How much ice remains in the system after it reaches equilibrium?
3. Would your answer to part b be different if both pieces of ice were added at the same time?

(specific heat of aluminum is 0.9 kJ/kg K and water is 4.18 kJ/kg K)

While unrealistic, we will examine the forces on a leg when one falls from a height by approximating the leg as a uniform cylinder of bone with a diameter of 2.3 cm and ignoring any shear forces. Human bone can be compressed with approximately 1.7 × 108 N/m2 before breaking. A man with a mass of 80 kg falls from a height of 4 m. Assume his acceleration once he hits the ground is constant. For these calculations, g = 10 m/s2.

Discuss the relative effectiveness of dieting and exercise in losing weight, noting that most athletic activities consume food energy at a rate of 300 to 400 Cal/h, while a single cup of yogurt can contain 325 Cal. Specifically, is it likely that exercise alone will be sufficient to lose weight? You may wish to consider that regular exercise may increase the metabolic rate, whereas protracted dieting may reduce it.

6. A long, straight wire has a 10.0-

1)A 75 kg cyclist races around a circular track at a constant speed of 20 m/s. The radius of the track is 50 m. Express both of your answers to the nearest whole number.

a) What is the acceleration of the cyclist?

b) What is the net force acting on the cyclist?

2)In the Bohr model of the hydrogen atom, an electron circles a proton in an orbit whose radius is 5.30 x 10^-11 m.

a) Find the magnitude of the gravitational force between the electron and the proton

b) Find the magnitude of the electrostatic force between the electron and the proton.

For both, express your answer in scientific notation, rounded to the nearest tenth.

3)Strictly speaking, Newton's law of universal gravitation, F = Gm₁m₂/r², is valid only if the masses are either point masses or __________________.

To receive full credit for any answer, you must explain your answers and include a logical and correct application of physics principles and/or definitions in your explanation.

If there is a mathmatecal solution or drawing to help understand the problem please include

1.    To compute the pressure difference between two points in a fluid, you must add the pressure differences determined from Bernoulli’s equation and Poiseuille’s law. a) Give an example of an actual situation where Bernoulli’s equation can be ignored in computing the pressure difference, and b) an example of an actual situation where Poiseuille’s law can be ignored. In both examples, the points must be chosen so that the distance between the two points is not zero. (Note that an actual situation means a real situation, one that occurs in nature or can be realized in the lab.)

Suppose the straight-line distance between New York and San Francisco is 4.1 × 106 m (neglecting the curvature of the earth). A UFO is flying between these two cities at a speed of 0.68c relative to the earth. What do the voyagers aboard the UFO measure for this distance?

The total energy of an object is 7.86 × 10¹² J, and its kinetic energy is 6.00 × 10¹² J. What is the mass m of the object?

A radar antenna is rotating and makes one revolution every 25 s, as measured on earth. However, instruments on a spaceship moving with respect to the earth at a speed v measure that the antenna makes one revolution every 45 s. What is the ratio v/c of the speed v to the speed c of light in a vacuum?

As observed on earth, a certain type of bacteria is known to double in number every 24 hours. Two cultures of these bacteria are prepared, each consisting initially of one bacterium. One culture is left on earth and the other placed on a rocket that travels at a speed of 0.932c relative to the earth. At a time when the earthbound culture has grown to 16 bacteria, how many bacteria are in the culture on the rocket, according to an earth-based observer?

1. Suppose that the Earth was thermally insulated from the rest of the universe so that it was an isolated system. Describe the entropy of the Earth as a function of time.

2. Consider taking two identical ice cubes out of the freezer. You place one in a cup and let it melt; you take the other and smash it with a hammer and then put it in an identical cup and allow it to melt. Compare the entropy changes of the two ice cubes.

3. Upon freezing, water becomes more orderly and its entropy decreases. Explain why this process does not violate the second law of thermodynamics.

Ip= 19A at Vp = 440V and Vs= 9000V. If the transformer is 95% efficient, how many turns are in the secondary coil? (efficiency e is the ratio of the power output to the power input or e = Ps/Pp). I know the result is Ns= (Vs Np) / Vp = 3680 turns, but why can't I use this below equation:

Ps/Pp = (Is Vs) / (Ip Vp) = 0.95

Is/Ip = Np/Ns

we have Np Vs / Ns Vp = 0.95

Ns= (Vs Np) / (0.95 Vp)

So why can't I use this equation [ Ns= (Vs Np) / (0.95 Vp) ] to find secondary coil.
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Could you please draw a diagram of this case. Please explain why I = 240V / (R + r) ? Where does r come from and what formula is this? a 240-V dc motor has an armature whose resistance is 1.8 ohms. When running at its operating speed, it draws a current of 14.0 A. Starting current is 133 A. What series resistance would be required to limit the starting current to 26.0 A? Could you also explain what is a back emf with simple definition? why does it act against applied voltage and reduce the current?

. On a horizontal, frictionless surface, a 9.00 kg object initially moving east at 4.00 m/s collides with a 3.00 kg object that was initially moving north at 10.0 m/s. After the collision, the three-kilogram object moves with a velocity o 12.00 m/s directed 32.0o north of east. (a) Calculate the velocity of the nine-kilogram object after the collision, and (b) determine by calculation the type of collision that occurred.

a) Radon undergoes alpha decay with a half-life of 3.8 days. What is its decay constant in s^-1?

b) Sr -90 (A=90, Z = 38) decays via β^- decay. Calculate the energy of the antineutrino (in keV) if the beta particle has a kinetic energy of 397 keV. Note - you can look the atomic masses up online.

c) What is the average binding energy per nucleon for Argon-40 (A=40, Z = 18) in MeV/nucleon? Note - keep 4 significant figures.

The 1.2 liter coffee pot is filled with 15 ° C water. What is the amount of heat used to heat and boil water when 50 cm3 of water is known to have evaporated? (Do not ignore the changed water density as the temperature changes. Water density 1000 kg / m3).

In the arrangement above, charge A is -46 nC, while charges B and C are each 67 nC.Each side of the triangle is 7.7 cms. Determine the magnitude of the electric field at the center of the triangle, in N/C.

What is the direction of the electric field in the previous problem? Express your answer in degrees measured counterclockwise from the positive x-axis.