The point charges in the figure below have the following values: q₁ = +2.7

Two hard rubber spheres, each of mass m = 13.8 g, are rubbed with fur on a dry day and are then suspended with two insulating strings of length L = 5.25 cm whose support points are a distance d = 2.70 cm from each other as shown in the figure below. During the rubbing process, one sphere receives exactly twice the charge of the other. They are observed to hang at equilibrium, each at an angle of θ = 10.7° with the vertical. Find the amount of charge on each sphere. (Assume the two spheres have charges q₁ and q₂ = 2q₁)

Deep-sea divers often breathe a mixture of helium and oxygen to avoid the complications of breathing high-pressure nitrogen. At great depths the mix is almost entirely helium, which has the side effect of making the divers' voices sound very odd. Breathing helium doesn't affect the frequency at which the vocal cords vibrate, but it does affect the frequencies of the formants. The text gives the frequencies of the first two formants for an "ee" vowel sound as 270 and 2300 Hz.

What will these frequencies be for a helium-oxygen mixture in which the speed of sound at body temperature is 720m/s ? (Use 350 m/s for the speed of sound in the air.)

A positive charge q is fixed at the point x = 0, y = 0, and a negative charge -2q is fixed at the point x = a, y = 0.

a) Derive an expression for the potential V at points on the x -axis as a function of the coordinate x . Take V to be zero at an infinite distance from the charges. (Express your answer in terms of the given quantities and appropriate constants).

V(x) =

b) At which positions on the x -axis is V = 0? (Enter your answers numerically separated by commas).

x/a =

c) What does the answer to part A become when x>>a ?

V =

d) Explain why this result is obtained.

An astronaut has left the International Space Station to test a new space scooter. Her partner measures the following velocity changes, each taking place in a time interval 10.9 s . What are the average acceleration in each interval? Assume that the positive direction is to the right.

Part A

At the beginning of the interval the astronaut is moving toward the right along the x-axis at 14.1 m/s , and at the end of the interval she is moving toward the right at 5.50 m/s .

Part B

At the beginning she is moving toward the left at 5.50 m/s , and at the end she is moving toward the left at 14.1 m/s .

Part C

At the beginning she is moving toward the right at 14.1 m/s , and at the end she is moving toward the left at 14.1 m/s .

1. how does proton therapy work

2. Clinical application of proton therapy

a)Find the x-component of vector v⃗  = (310 m/s , 45 ∘ above +x-axis).

b)Find the y-component of vector v⃗  = (310 m/s , 45 ∘ above +x-axis).

The average intensity of a particular TV station

Which of the following statements are true?
True False  Magnetic field lines always start at a North and end at a South pole.
True False  When placing a dipole magnet into a magnetic field, it will be accelerated perpendicular to the field lines.
True False  The force on a moving charge is perpendicular to both the field and its velocity.
True False  The larger the charge of a moving particle, the more it will accelerate inside of a magnetic field.

Which  process, conduction, convection, or radiation is most involved with the  distribution of heat around the earth?

Write about czochralski method (melt) in half of a sheet

Ionization chambers, proportional counters and Gieger-Muller counters are all gas-filled radiation detectors. Sketch a graph of the signal (pulse of charge collected) as a function of the voltage applied. Describe what happens to the number of ion pairs collected as a function of Applied Voltage, (from very low voltage to high voltage). In particular indicate the regions of this graph which define the three different detector types.

(a) Find the photon energy and wavelength for the series limit (shortest wavelength) in the Balmer series (n_f = 2) for the hydrogen atom.
___________eV
_________ nm

(b) Calculate the wavelength for the three longest wavelengths in this series.
longest
____________nm
second longest
____________nm
third longest
____________nm

Starting with 2.50 mol of nitrogen gas (N2) in a container at 1.00 atm pressure and 20.0 °C temperature, a student heats the gas at constant volume with 15.2 kJ of heat, then continues heating while allowing the gas to expand at constant pressure, until it is at twice its original volume.

1. What is the final temperature of the gas?

2. How much work was done by the gas?

3. How much heat was added to the gas while it was expanding?

4. What is the change in internal energy for the whole process?

A small block with mass 0.0400 kg is moving in the xy-plane. The net force on the block is described by the potential- energy function U(x,y)= (5.90 J/m2 )x2-(3.90 J/m3 )y³.

a- What is the magnitude of the acceleration of the block when it is at the point x= 0.29 m , y= 0.66 m ?

b- What is the direction of the acceleration of the block when it is at the point x= 0.29 m , y= 0.66 m ?