(a) What is the advantage and disadvantage images from radioactivity compared imaging from ultrasound, x-ray and CT?

(b)Explain in detail the operation of a PET scanner, illustrating your points by using more than one drawing, appropriately labeled.

One of the many isotopes used in cancer treatment is gold ¹⁹⁸₇₉Au, with a half-life of 2.70 days. Determine the mass of this isotope that is required for an activity of 200 Ci.

I got an answer of 30.99g but this was wrong.

Air enters a nozzle steadily at 280 kPa and 77°C with a velocity of 70 m/s and exits at 85 kPa and 320 m/s. The heat losses from the nozzle to the surrounding medium at 20°C are estimated to be 3.2 kJ/kg.

The table for the ideal-gas properties of air is given below.

Determine the exit temperature. (Round the final answer to one decimal).

The exit temperature is ______K

Determine the total entropy change for this process. (Round the final answer to four decimal places.) (You must provide an answer before moving on to the next part.)

The total entropy change for this process is ______kJ/kg·K.

A 31 g ice cube at -15.0oC is placed in 139 g of water at 48.0oC. Find the final temperature of the system when equilibrium is reached. Ignore the heat capacity of the container and assume this is in a calorimeter, i.e. the system is thermally insulated from the surroundings. Give your answer in oC with 3 significant figures.
Specific heat of ice: 2.090 J/g K
Specific heat of water: 4.186 J/g K
Latent heat of fusion for water: 333 J/g

Two objects undergo an elastic collision. Object 1 has a mass of 1.35 kg and object 2 a mass of 3 kg. Just prior to the collision, object 1 has a kinetic energy of 77 J and object 2 is at rest. What is the initial velocity of Object 1? What is the total kinetic energy of the two cart system after the collision? What is the total momentum of the two cart system after the collision?

Research and then name the fundamental Raman modes of SWCNTs and describe briefly their energy and source in the nanotubes.

The space elevator project is an effort that intends to place an elevator system grounded on the Earth into geosynchronous orbit. Carbon nanotubes are the only material strong enough to make this elevator. What is it about carbon nanotubes that make people think this way? Do you think a space elevator is possible? What are some potential issues?

The electric potential at a position located a distance of 22.5 mm from a positive point charge of 8.20×10^-9C and 13.0 mm from a second point charge is 1.06 kV. Calculate the value of the second charge.

Also...

A positive charge of 4.40 μC is fixed in place. From a distance of 4.40 cm a particle of mass 6.00 g and charge +3.90 μC is fired with an initial speed of 66.0 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?

A mass of 9 kg rests on a floor with a coefficient of static friction of 0.92 and coefficient kinetic friction of 0.37. One force is applied vertically downward of 22 Newtons and another force is applied at an angle of 26 degrees below the horizontal. Calculate what the magnitude this force needs to be in order to begin to move the mass. If that force is removed and another force is applied at an angle of 26 degrees above the horizontal (the downward force is still there), calculate the force needed to begin to move the force for that situation. How much more force is needed to begin the mass, in Newtons, when the force is angled below the horizontal compared to above the horizontal?

a. Explain what is meant by the barrier potential and how it is formed before any bias is applied. [3 marks] b. When the diode is forward biased: i. What happens to the barrier potential? [1 mark] ii. What happens to the depletion region? [1 mark] iii. Indicate on your diagram the directions in which the holes and electrons move. [2 marks] c. Explain what is meant by the forward voltage drop of a diode. [2 marks] d. When the diode is reverse biased: i. What happens to the depletion region? [1 mark] ii. What causes the reverse bias leakage current? [2 marks]

5. Two charges with a (charge) ratio of 1:3 are 30cm apart from each other in vacuum (free space).

   1. a) How far do both charges need to be placed in water when we want to achieve the same interaction force in both cases? (εr,water@20°C = 80.1)

1) a car battery is rated at 90 amphour. How much charge is available in the battery?

2) A +2.6 uc point charge is placed at the center of a cube with sides of length 7.5cm. What is the electric flux through two sides of the cube?

3) The amount of charge flowing though a circuit caries with time according to.. q(t)=(0.2t²-0.3t), with q in coulombs and t in seconds. Find the current through the circuit at t = 1.5 seconds.

4) Calculate the acceleration of an electron placed in a uniform electric field of magnitude 4.5*10⁵ N/C.

A conducting single-turn circular loop with a total resistance of 7.50 Ω is placed in a time-varying magnetic field that produces a magnetic flux through the loop given by ΦB = a + bt2 − ct3, where a = 8.00 Wb, b = 15.5 Wb/s−2, and c = 7.50 Wb/s−3. ΦB is in webers, and t is in seconds. What is the maximum current induced in the loop during the time interval t = 0 to t = 1.55 s? (Enter the magnitude.)

Can a person, in principle, travel from Earth to the galactic center (which is about 2.30

1) An evacuated tube uses an accelerating voltage of 44 kV to accelerate electrons to hit a copper plate and produce X-rays. Ignoring relativistic effects, what would be the maximum speed of these electrons?

2) A battery-operated car uses a 12.0-V system. Find the charge the batteries must be able to move in order to accelerate the 600 kg car from rest to 30.0 m/s.

3) I want to accelerate an electron to the speed of sound (343 m/s) by electrostatic force alone. To do so I’ve devised a way to store as much charge as I’d like at a single fixed point which will be located 0.35 m from the electron. How much charge do I need to accumulate to accomplish my goal?