A 65.0 kg man is riding on a 12.5 kg bicycle. Together they have a kinetic energy of 2.80 x 10^3. If the bicycle has wheels with radii of 0.450 m, then their frequency of rotation is

Calculation of half-life for alpha emission using time-independent
Schrodinger Equation using the following following information:
Radionuclide: 241-Am (Z=95); Ea = 5.49 MeV; Measured Half-Life~432y

Follow the steps involved and show your work for each subset question, not the
final answer:
(a) Evaluate the well radius [=separation distance (r) between the center of
the alpha particle as it abuts the recoil nucleus];
(b) Evaluate the coulomb barrier potential energy (U) for the well;
(c) Estimate the separation distance (r*) from the center of the potential well
where the coulomb potential equals the energy of the alpha particle;
(d) Assuming a square shaped single barrier of height “U”, evaluate the
tunneling probability by solving for the transmission coefficient and use of
the associated separation (=r*-r);
(e) Calculate the frequency with which the alpha particle strikes the well
boundary to try to get out of the well;
(f) Calculate the half-life and compare it with the known half-life for alpha
emission from 238U;
(g) Use the spatially-averaged effective approximation for the height of the
barrier by integrating the variation of “U” with distance from “r” to “r*” and
re-calculate the half-life and compare it with the known half-life for alpha
emission from 238U;
(h) Approximate the hyperbolic shaped barrier variation outside of the well
by breaking them up into 5 progressively reduced height square shaped
barriers, each with a width = (r*-r)/5 and calculate the tunneling
probabilities associated with each segment;
(i) Re-calculate for the half-life combining the probabilities from each of the 5
bins, and compare the value with the known half-life.

What must be the position of an object in order that it may be seen distinctly through a +9.0 D lens placed 2.9 cm in front of an eye, the eye being accommodated for a distance of 35.5 cm? Give your answer in cm as a distance to the lens.

Marc drives like a maniac. His defense is always "It’s OK, I know the physics of driving so I do it safely". Marc is coming up to a horizontal turn of radius r = 150 m. Since Marc is a physicist, he just knows the coefficient of static friction between the tires and the road is µ = 0.45. If the center of mass of Marc’s car is xcm = 60 cm above the ground and his car’s wheel base is ` = 1.3 m, determine the following:

(a) a formula for the maximum speed Marc can complete the turn without flipping the car.

(b) a formula for the maximum speed Marc can complete the turn while remaining on the road (hint, you will have to compare the value from two formulas).

(c) whether Marc can safely complete the turn if his speed is 100 km/h? What about at 80 km/h?

(d) Show that if µs < ` 2xcm , then it is impossible to flip your vehicle.

(e) The above ratio is something that vehicle engineers must be aware of (as it is a safety thing). Moving vans, obviously, have a much higher center of gravity, however, due to width constraints (width of lanes on the road, parking spots, etc), they are not able to make the wheelbase that much wider. If the wheelbase of a moving van is 2 m and it’s center of mass (when modestly loaded) is 5 ft, is it able to flip (using the same µs as above)?

The weight of an astronaut on Earth surface is 950 N. What is the astronaut weight in a satellite orbiting Earth at an altitude of 500km with a speed of 450 m/s? (g=9.8 m/s2 and REarth = 6400 km). Select one: a. 790 N b. 815 N c. 852 N d. 1020 N

1. Discuss any ethical or practical considerations that might arise from application of Ultraviolet light.

2. How different wavelengths of the electromagnetic spectrum are applied in real life. These might include (but are not limited to) environmental impact, safety concerns, or issues of effectiveness.

Your summary must be in your own words.

Explain both Newton’s and Einstein’s views of gravity between earth and the moon. Make sure your answer is detailed and specific.

The closest distance a book can be read from a pair of reading eyeglasses (Power = 2.06 dp) is 27.5 cm. What is the near distance? (Assume a distance between the eyeglasses and the eyes to be 3.00 cm)

1. If I=35,000 time the threshold of hearing, what is the difference in db?

2. Mathematically prove that the threshold of pain is 130db. (Mathematically prove means to show an equation and solution)

3. If one speaker is quieter than another, what is the reduction in db?

a. If it has only 1/3 the intensity of the other?

b. If it has only 1/6 the intensity of the other?

4. Mathematically prove that a 10db increase is 10 times the power, and only 3.16 times the pressure/voltage. (Show an equation and solution)

5. Describe the difference between A weighting and C weighting (be thorough but concise).

True or false? The asteroid belt is inside the Sun’s Roche limit and thus could not overcome the Sun’s tidal forces to form a planet.

True or false? The time interval when a specific comet’s tail is long is much less than the time interval when that comet’s tail is short.

True or false? The asteroid belt was probably produced when two large, fully formed terres-trial planets collided with and shattered each other.

True or false? Most meteor showers occur when a random comet or asteroid enters Earth’s atmosphere and then breaks up into many pieces.

True or false? Most of the Kuiper-belt objects are between the orbits of Neptune and the Oort cloud.

True or false? The peculiar distribution of certain types of Kuiper-belt objects suggests the gravitational influence of a very distant, massive “Planet Nine” that astronomers are now trying to find.

1a) A copper wire 4.4 um in diameter and 318.9 um long has a temperature at one end of 35 °C and 32 °C at the other. Calculate the rate of heat flow through the wire, in Watts. (For copper kC= 400 W/mK)

1)b) The thermal conductivity of air at room temperature is 0.028 W/mK and its density is 1.16 Kg/m³. The average air molecule travels at 525.4 m/s and collides about every 267 ps with another air molecule. How much heat (in J) is needed to raise the temperature of a cubic meter of air by 10 °C?

Consider a system of an 85.0 kg man, his 20.5-kg dog, and the earth. The gravitational potential energy of the system increases by 1.90 10³ J when the man climbs a spiral staircase from the first to the second floor of an apartment building. If his dog climbs a normal staircase from the same first floor to the second floor, by how much does the potential energy of the system increase (in J)?

Two blocks, of 2.0 kg each, are attached by a string and slide down a ramp making an angle of 50° with the horizontal. Mass ?1 has a coefficient of kinetic friction of 0.60, and mass ?2 has a coefficient of kinetic friction of 0.40. 10. Find the acceleration of the blocks. 11. Find the tension in the string.

A 5.61μC and a -2.04μC charge are placed 19.0cm apart. Where can a third charge be placed so that it experiences no net force? [Hint: Assume that the negative charge is 19.0cm to the right of the positive charge.]