Derive the exponential expression that describes the radioactive decay in the number of nucleotides, N over a time, t. Give an example of another physical phenomenon which is described by an exponential relationship such as this. b) A radioactive nucleotide has a half-life of 20.0 years. What fraction of an initially pure sample of this nuclide will remain at the end of (i) 50.0 years, and (ii) 100.0 years. c) Give an account of nuclear binding energy, accompanied by a labelled graph of binding energy per nucleon versus the number of nucleons that explains why some elements undergo fission reactions whilst some undergo fusion reactions. d) Calculate the nuclear binding energy in MeV of the 92 protons and 146 neutrons in the nucleus of a 238U atom. Note the following: the mass of 238U atom = 238.05079 u; the mass of the Hydrogen atom = 1.00783 u; and the mass of the neutron = 1.00866 u, where u is the atomic mass unit.

(a) Describe the nuclear processes of alpha and beta decay, and describe what parameter is increasing in the nucleus as a result of these decays. [3] (b) Where a stationary neutron combines with a proton to form a deuteron, a gamma ray of energy 2.2233 MeV is emitted. The masses of the proton and the deuteron are 1.007276467 u and 2.013553212 u, respectively. Determine the mass of the neutron, stating any laws used and defining variables. [4] (c) Uranium ore mined today contains 0.72% of fissionable 235U, with the remainder being 238U. For use in a reactor, the ore needs to be refined to increase the fraction of 235U to 3%. How many years ago would natural uranium ore have been a practical reactor fuel, with a 235U/238U ratio of 3.0%? [3] Take 235U to have a half-life of 7.0 × 108 y and 238U to have a half-life of 4.5 × 109 y

Present an application of a wave phenomena to studies in a field of science or engineering other than physics. Your examples may be taken from, but are not limited to, sound engineering, instrument making, medical imaging, non destructive testing, oil explorations, earth quake prediction, and Tsunami warning systems. No matter what field you choose the wave phenomena.

what media, if any, do the waves propagate?

Are the waves in this application transverse, longitudinal, or both? If either transverse or longitudinal waves are missing from the application explain why?

On what parameters of the media (pressure, temperature, mass, density,... ) does the wave speed depend?

In general, what is the relationship between the wavelength, the frequency, and the wave speed?

Define diffraction, diffusion, constructive interference, and destructive interference as general properties of waves.

Discuss how diffraction, diffusion, constructive interference, and destructive interference appears in your application. If it does not appear explain why not.

Choose true or false for each statement regarding concave mirrors.
true false  If an object is placed 4.1 cm from a concave mirror with f = 4 cm, then its image will be enlarged and real.
true false  A concave mirror produces an enlarged real image when the object is placed just beyond its focal point (Region 2).
true false  If an object is placed 7.9 cm from a concave mirror with f = 4 cm, then its image will be enlarged and real.

Choose true or false for each statement regarding convex mirrors.
true false  If an object is placed 7.9 cm from a convex mirror with f = 4 cm, then its image will be reduced and real.
true false  A convex mirror produces a reduced real image when the object is placed far beyond its focal point (Region 1).
true false  If an object is placed 4.1 cm from a convex mirror with f = 4 cm, then its image will be reduced and real.

Choose true or false for each statement regarding the sign conventions for mirrors.
true false  Virtual images appear behind a mirror and have a positive value for the image distance.
true false  The magnification m is positive for inverted images.
true false  The magnification m is negative for upright images.

Magnetic flux lines, by itself, is not very useful. You can’t see them. You can’t touch them. They can’t be detected by sensors. So, by themselves, they are not very useful. Yet, as a concept they very useful. But within a context, when they are changing in time, in the vicinity of other things (what things?) they are important. Explain where Magnetic Flux is useful, where it is important?

A 4.0-cm-diameter parallel-plate capacitor with a 1.0 mm spacing is charged to 1000 V. A switch closes at t =0s, and the capacitor is discharged through a wire with 0.20? resistance.

Part A

Find an expression for the magnetic field strength inside the capacitor at r =1.0cm as a function of time t (where t is in ps).

Part B

Draw a graph of B versus t.

Singly ionized (one electron removed) atoms are accelerated and then passed through a velocity selector consisting of perpendicular electric and magnetic fields. The electric field is 160 V/m and the magnetic field is 3.18×10^?2 T . The ions next enter a uniform magnetic field of magnitude 1.73×10^?2 T that is oriented perpendicular to their velocity.

(A) If the radius of the path of the ions in the second magnetic field is 17.1 cm , what is their mass?

Consider a beam of light passing from air into glass (refractive index 1.5) at an angle of 30 degrees from vertical. Calculate

- The angle of the reflected light

- The angle of the refracted light

- The intensity of the reflected light

- The intensity of the refracted light

Why can you electroplate using metals like copper or silver but not materials like carbon or oxygen? (Hint: Look up the difference between metals and non-metals.)

Two vehicles are approaching an intersection. One is a 2300 kg pickup traveling at 13.0 m/s from east to west (the ?x- direction), and the other is a 1300 kg sedan going from south to north (the +y?direction at 21.0 m/s ).

Q1: Find the x -component of the net momentum of this system.

Q2: Find the y-component of the net momentum of this system.

Q3: What is the magnitude of the net momentum?

Q4: What is the direction of the net momentum?

Four traveling waves are described by the following equations, where all quantities are measured in SI units and y represents the displacement.

Which of these waves have the same speed?

      I:    y = 0.12 cos(3x - 24t)

      II:  y = 0.15 sin(6x + 32t)

      III: y = 0.13 cos(6x + 24)

      IV: y = -0.27 sin(3x - 42t)

Q3a.

Define the specific heat capacity, and state its units.

b.

A Cu bar, 0.5 m long and 1 cm in thickness, is placed in a stream of boiling water at one end, and in a 2 kg block of ice at -10°C the other end. The thermal conductivity of Cu is 380 Wm-1K-1, the specific heat capacity of ice is 210 Jkg-1K-1 and the latent heat of melting of ice is 0.34 x106 Jkg-1. How long will it take to completely melt the ice block?

c.

Using the Thermal Shock Resistance equation explain what mechanical and physical properties would contribute to increased thermal shock resistance, and why silica is good at resisting thermal shock.

d.

Define convection.

e.

State the equation for the Rayleigh Number, defining all of the terms.

1(a)
Draw a schematic representing a dislocation, in 2D.
(b)
Describe what is meant by work-hardening? Explain with an example.
(c)
Assume you are stretching a bar of metal that undergoes work hardening. What would the Stress vs Strain diagram of such a material look like, showing deformation behaviour?
(d)
Define the Following:
(i) What is a Fracture?
(ii) Define the types of Fracture.
(iii) Draw the types of Fractures.
(iv) What is Fracture Toughness?
(v) What are Stress Concentrators?

(e)

State at least two situations in which the possibility of failure is part of the design of the component or Product.

1.(a)
Define what are Crystalline Solids and Amorphous Solids?
(b)
Explain, with a two-dimensional representation, the amorphous and crystalline forms of SiO2?
(c)
The density of matter largely depends on the atomic weight of the atoms and how closely packed they are in the crystal structure. The atomic weight of nickel is 58.70 amu, and it has a face-centred cubic structure, with a lattice parameter of 3.52 Å. Estimate the theoretical density of nickel.