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 ?

A soccer player kicks the ball toward a goal that is 27.6 m in front of him. The ball leaves his foot at a speed of 18.5 m/s and an angle of 31.2° above the ground. Find the speed of the ball when the goalie catches it in front of the net. (Note: The answer is not 18.5 m/s.)

I keep getting a final velocity of 13.92797m/s but its incorrect. Please show your work so I can see what I'm doing wrong.

Internal injuries in vehicular accidents may be due to what is called the "third collision" The first collision is the vehicle hitting the external object. The second collision is the person hitting something on the inside of the car, such as the dashboard or windshield. This may cause external lacerations. The third collision, possibly the most damaging to the body, is when organs, such as the heart or brain, hit the ribcage, skull, or other confines of the body, bruising the tissues on the leading edge and tearing the organ from its supporting structures on the trailing edge.

A) Why is there a third collision? In other words, why are the organs still moving after the second collision?

B) If the vehicle was traveling at 60 mph before the first collision, would the organs be traveling more than, equal to, or less than 60 mph just before the third collision?

Explain your answers in essay form:

A 120 V rms voltage at 60.0 Hz is applied across an inductor, a capacitor, and a resistor in series. If the peak current in this circuit is 0.84840 A, what is the impedance of this circuit?

• For two objects dropped at two different times from the same location (e.g. a bridge), while both are still

  in free-fall describe how their velocities and their distances change through time (neglecting air

  resistance).

• An example would be appreciated

A 0.50-kg mass vibrates according to the equation x = 0.35 sin (5.50 t) where x is in meters and t is in seconds. Determine (A) the amplitude, (B) the frequency, (C) the total energy, and (D) the kinetic energy and potential energy when x = 0.3m Please Explain.

(1) A block is placed on a wooden plank, which is initially horizontal. One end of the plank is slowly raised to make it more and more inclined, and for a while the block stays in place on the plank and doesn't slide due to static friction. Finally, when the plank reaches an incline of 56.3^o above horizontal, the block begins to slide. What is the  coefficient of static friction between the block and the plank?

(2) Continuing the story... after the block begins sliding down the incline at 56.3^o, you measure its acceleration down the plank as 7.42 m/s². What is the coefficient of kinetic friction between the block and the plank?

These will be clicker questions on Wednesday, and we will work together through some problems involving tension and pairs of objects.

Suppose a 10 kg ball makes a one dimensional collision with a 5 kg ball. Think about what could happen to the velocity of the 5 kg ball as a result of the collision. Could it remain unchanged? Could it increase? Could it decrease? Is it possible for both balls to end up traveling in the same direction after the collision? For each result you think could happen, please briefly explain why and offer an example of starting conditions that would cause that result. If you think a certain result couldn't happen, please also briefly explain why.

A  green laser operates at 488.0 nm with an output power of 2.5 mW. Calculate the average output in photons/s (“photon flux”). What would the output power be for the same flux of 244.0 nm photons? What would the photon flux be for a 488.0 nm laser operating at 5.0 mW?

A charge of -5.50nC is spread uniformly over the surface of one face of a nonconducting disk of radius 1.00cm

Part A

Find the magnitude of the electric field this disk produces at a point P on the axis of the disk a distance of 3.00cm from its center.

Part B

Suppose that the charge were all pushed away from the center and distributed uniformly on the outer rim of the disk. Find the magnitude of the electric field at point P.

Part C

If the charge is all brought to the center of the disk, find the magnitude and direction of the electric field at point P.

Part D

Why is the field in part (a) stronger than the field in part (b)?

Part E

Why is the field in part (c) the strongest of the three fields?