b. Compare what happens to potential energy, kinetic energy, and total energy as the skater moves up and down the track. What general statement can you make about the relationship between potential and kinetic energy?

c. Notice that the bar entitled “Thermal” energy does not deviate from zero. This represents an energy that is transformed into "heat" energy. What must be true of this skate park for this to remain at zero?

d. Vary the skater's Mass with the slider on the right while the simulation is running. Describe the similarities and differences that changing the mass has on the bar graphs.

e. Click on the Friction tab at the bottom and choose the parabola track. Place the skater at the top. Examine the bar graphs as the skater oscillates back and forth. What is happening to the energies present? Explain how you know that energy is still being conserved.

f. Run the simulation as in part “e” until the skater comes to a stop. What form did the skater’s initial energy end up as?

Use the above graphs to answer the questions below. a. Estimate roughly where was he located at the times listed below:

• zero seconds? ___________________

• 6.8 seconds? __________________

• 8.1 seconds? _________________

• 5.3 seconds? _________________

b. If his maximum height is 4 m (measured from the bottom of the track), what is his height at the times below

• zero seconds? ___________________

• 6.8 seconds? __________________

• 8.1 seconds? _________________

• 5.3 seconds? __________________

Examine the kinetic energy curve on the graph above. Given that his mass was 75kg calculate his speed at the times below using Ek = ½mv2 .

Speed at zero seconds: show any work below v0 = ______________ m/s

Speed at 6.8 seconds: show any work below v0 = ______________ m/s

Speed at 8.1 seconds: show any work below v0 = ______________ m/s

Speed at 5.3 seconds: show any work below v0 = ______________ m/s

Choose the Friction tab (bottom of screen) and select the half-pipe track. Now select on Grid. This will provide a scale for you to measure heights in meters. You may assume that the mass of the default skater is 75kg. Run the simulation and sketch the Energy vs time graphs below. You know the shapes of these from above, you simply need to determine the transition times (period of motion). Use a stopwatch to get a rough idea. Be sure to include a legend to represent your different energy curves.

6. The Very Long Baseline Array radio interferometer (VLBA) has a longest baseline of 8000 km and can operate at frequencies as high as 44 GHz. The Keck interferometer has a baseline of 100 m and operates at a near-infrared wavelength of 2 micron. (a) Which instrument has the highest angular resolution (smallest diffraction angle)? (b) For the VLBA, what is the smallest distance two radio transmitters could be on the Moon that could still be discerned? Use a lunar distance of 384,000 km.

If you look at the US production of crude oil, you can see that the data trend for peak oil occurring around 1970. Since then it has declined with a plateau here and there. However around 2010, US oil production has increased quite a bit. What do you think is the cause for increase in oil production at the time?

A cannon tilted up at a 35.0 ∘ angle fires a cannon ball at 82.0 m/s from atop a 13.0 m -high fortress wall. What is the ball's impact speed on the ground below? Express your answer with the appropriate units.

1. One goal of EHRs is to facilitate providers

Planet X has a moon that has a very elliptical orbit. Its furthest point from the planet X is 4 × 10^8 m and its closest point is 3 × 10^8 m. If its speed at the furthest point is 700 m/s, what is its speed at its closest point?

The mass of planet X is 2.68 X 10^24 kg and the radius of planet X is 4079 km. (please show work and drawing)

Question 1 a. An engineer designing an electron microscope wants to ensure that the final instrument can resolve features separated by 10-9 m and therefore decides that the de Broglie wavelength of the electrons should be 50 times shorter, i.e. 2 x 10-11 m. NOTE: in answering this question, ignore relativistic effects and assume that classical mechanics applies.

i. What would be the speed of the electrons? [1 mark]

ii. What voltage must be used for accelerating the electrons to achieve this objective? [2 marks]

iii. Estimate the probability that these electrons can tunnel through a barrier of thickness 10-9 m, if the barrier is 5 eV higher than the electron’s kinetic energy? You may use the approximate expression for barrier tunnelling T ! e−2bL [4 marks]

iv. If there is a 10% uncertainty in the speed of the electrons, what is the minimum uncertainty in their position? [3 marks]

b. i. Why are the energy levels of a confined electron quantised (e.g. in an infinite potential well), while a free electron can take a continuous range of energies? [2 marks]

ii. An electron is confined to an infinite potential well of width 0.25 nm. What is the lowest energy (ground state) for the confined electron? [2 marks]

iii. Calculate the energy of the first and second states of the electron in the infinite potential well (i.e. n = 2,3,4) [2 marks]

iv. Calculate the wavelength of the photon emitted when an electron in the first excited state drops to the ground state. [1 mark]

v. Qualitatively describe the difference in the energy levels of the infinite potential well we have been investigating, and a finite potential well of depth 50 eV. Your answer should include a sketch of the probability density for an electron in the ground state for both the infinite and finite potential well.

A +2.00 nC point charge and -3.00 nC point charge are placed along the x-axis at  x = 1.0 m and x = 2.0 m, respectively. Where must a third charge, q, be placed along the x-axis so that it does not experience any net electric force due to the other two charges

Consider a sample of ideal gas (0.50 moles) confined in a piston assembly that has diathermal walls (i.e. the walls allow heat exchange). The assembly is in contact with a thermal reservoir that holds the temperature constant at 300.K.

a) Suppose the ideal gas undergoes reversible isothermal compression from 25.0 L to 10.0 L. Calculate ΔS, ΔSsurrounding, and ΔStotal, where total = universe.

b) Suppose the ideal gas had instead been compressed isothermally by an external constant pressure from 25.0 L to 10.0 L. First determine the value of the minimum constant pressure for this process (in Pascals). Then, calculate ΔS, ΔSsurrounding, and ΔStotal.

Provide a diagram for each situation. A 45kg woman is riding on an elevator. What are her net force, force of gravity, and normal force for her when:

1) The elevator is stationary on the 20th floor of a building

2) The elevator has a downward acceleration with a magnitude of 1.5 meters per second squared.

3) The elevator has a constant downward velocity of 3 meters per second.

4) The elevator accelerates upward with a magnitude of 1.5 meters per second squared to stop at the 5th floor

5) The elevator cable suddenly breaks and the elevator undergoes free fall/

what do nuclear technology and physics share in common? (please answer in depth)

3. A cubical Gaussian surface encloses a net charge. Each edge of the cube has length 4.0 m. The cube is drawn such that four of its six faces are parallel to the z direction. The net electric field is such that the electric field lines skim each of these four faces. On the top face, the electric field ?⃗⃗ ? = +25?̂ N/C and on the other face ?⃗⃗ ? = −40?̂ N/C. Sketch the cubical Gaussian surface, indicating the z direction, ?⃗⃗ ? and ?⃗⃗

a. Determine the net charge the Gaussian surface encloses. b) Would any of your calculations be affected if you used a spherical Gaussian surface instead of a cubical one? Justify your answer.

A stretched string fixed at each end has a mass of 43.0 g and a length of 7.20 m. The tension in the string is 47.0 N. (a) Determine the positions of the nodes and antinodes for the third harmonic. (Answer from smallest to largest distance from one end of the string.)

nodes

______m

______m

______m

______m

antinodes

______m

______m

______m

(b) What is the vibration frequency for this harmonic? Hz

1. Boltzmann statistics predict the probability that atoms or particles will be at the level of
The energy E (s) is equal to P (s) where
P (s) = e ^ −E (s) ⁄kT / Z
Where Z is the Partition function and Z = ∑ e ^ −E (s) ⁄kT

1.1 One hypothetical particle has 3 energy levels, -0.05 eV, 0 eV and 0.05 eV. Write a graph between Z and kT and
Describe the graph (Recommended: Use programs like Mathematica)
1.2 If the particle is in balance with the environment (Reservoir) at 300 K, find the probability that the particle will be at the energy level
all three
1.3 If the particle is in balance with the environment (Reservoir) at 1000 K, find the probability that the particle will be at the energy level
All three compare with the result in item 1.2.

discuss the terrestrial /gas giant distinctions based on their rotation speeds,oblateness and magnetic fields?