As a physics demonstration, you want a special bowling ball made to demonstrate exactly 1 kg·m2, so that your students can rotate the ball about its center of mass to get a "feel" for how "big" 1 kg·m2 is. The bowling balls most familiar to your students has a weight of 15.4 pounds and have a circumference of 25.5 inches, but do not have a moment-of-inertia equal to 1 kg·m2. Since the sporting goods manufacturer has no understanding of how \"big\" 1 kg·m2 is, calculate the diameter of the demo bowling ball (in inches) it will need to manufacture. Assume that bowling balls are solid, with a constant density.
In: Physics
63. Use Max Planck’s quantum theory to explain the following behaviour of photoelectrons.
a) Low-intensity light does not release any photoelectrons. What will happen if the light
is made brighter? Explain your reasoning.
b) Low-intensity light releases photoelectrons. What will happen if the light is made
brighter? Explain your reasoning.
c) Low-intensity light does not release any photoelectrons. What will happen if the
frequency of the light is gradually increased? Explain your reasoning.
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3. List some types of optimization algorithms
for photons and for protons planning.
Compare the dose distribution of Photon IMRt with the proton
IMPT.
How are the organs at risk protected in photon therapy and how are
in Proton therapy?
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Two events are observed by inertial observer Stampy to occur a spatial distance of 15 c·s apart with the spatial coordinate of the second larger than the spatial coordinate of the first. Stampy also determines that the second event occurred 17 s after the first. According to inertial observer Philip moving along Stampy’s +x axis at unknown velocity v, the second event occurs 10 s after the first. (1 c·s = 1 light-second = unit of distance.)
a) Given Philip measures the spatial coordinate of the second event to be larger than the first, determine v.
b) How far apart spatially (in c·s) do the two events occur according to Philip?
c) Does there exist an inertial reference frame v < c in
which the second event can occur before the first? Briefly explain
in one sentence at most.
d) Inertial observer Kenny observes the proper time between the two
events. How fast along Stampy’s +x axis does Kenny move?
(Note: Each part of this question can be done independently of any other. In part a, depending on how you solve it, you might obtain two answers as solutions of a quadratic, but one of them is extraneous, because it violates the premise in part a. If you are careful, you can avoid the quadratic at the outset, but it requires you to solve part b first.)
In: Physics
Could you put the helium nucleus (also known as an "alpha particle") somewhere on a line between the proton and electron where it wouldn't feel a net force? Why or why not?
In: Physics
A tortoise and hare start from rest and have a race. As the race begins, both accelerate forward. The hare accelerates uniformly at a rate of 1.2 m/s2 for 4.4 seconds. It then continues at a constant speed for 11.8 seconds, before getting tired and slowing down with constant acceleration coming to rest 81 meters from where it started. The tortoise accelerates uniformly for the entire distance, finally catching the hare just as the hare comes to a stop.
1)
How fast is the hare going 3.1 seconds after it starts? See solution
2)
How fast is the hare going 12.5 seconds after it starts?
See solution
3)
How far does the hare travel before it begins to slow
down?
m
4)
What is the acceleration of the hare once it begins to slow
down?
m/s2
5)
What is the total time the hare is moving?
s
6)
What is the acceleration of the tortoise?
m/s2
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In a student experiment, a constant-volume gas thermometer is calibrated in dry ice (−78.5°C) and in boiling ethyl alcohol (78°C). The separate pressures are 0.896 atm and 1.629 atm. Hint: Use the linear relationship P = A + BT, where A and B are constants.
(a) What value of absolute zero does the calibration
yield?
(b) What pressure would be found at the freezing point of
water?
(c) What pressure would be found at the boiling point of water?
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Please answer the following questions clearly.
1) If two quantum states differ only by a phase factor, are they considered the same ? if so in what sense ?
2) Explain entaglement quickly?
3) why is the composite of quantum states is given by a tensor product whereas the composite of a classical states is given by a Cartesian product?
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Two spheres have the same diameter and mass, but one is solid and the other one is hollow. Assuming homogeneous densities and putting the origin at the center, calculate the inertia tensor of each sphere.
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What are the steps that you need to take when solving a problem using Ampere's Law?
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(a) (i) What particles inside of an atom make the biggest contribution to its magnetic moment? (ii) What are the two types of angular momentum that are involved?
(b) You are given a “term” 3P. (i) What is it describing? (ii) What values are associated with it? (iii) Is it a type of coupling? If so what kind?
(c) ( What if you instead say 3P2? (i) What is this called? (ii) What is the meaning of the extra label?
(d) ( These correspond to electron configurations with 2 electrons in three p suborbital. (The usual notation with 2 arrows.) (i) Fill in the arrows (electrons) to give one configuration that is part of 3P term. (ii) Give a configuration that violates Pauli exclusion.
In: Physics
1. What ROTATIONAL concepts are the HARDEST for you to understand and WHY? You can make an answer from your own experience, 150+ words needed
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In the simulation, for the Rutherford model, which of the following possible observations is correct when you use greater energies?
The incoming particles can reach closer to the nuclei.
Their trajectories bend more.
The particles lose more energy before exiting the target area.
The particles spread over a larger area.
The particles are able to break apart some of the target nuclei.
The particles excite higher electronic energy states.
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show that the relaxation time for a heavily damped rlc circuit is RC
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A target in a shooting gallery consists of a vertical square wooden board, 0.230 m on a side and with mass 0.700 kg , that pivots on a horizontal axis along its top edge. The board is struck face-on at its center by a bullet with mass 1.60 g that is traveling at 355 m/s and that remains embedded in the board.
A. What is the angular speed of the board just after the bullet's impact?
B. What maximum height above the equilibrium position does the center of the board reach before starting to swing down again?
C. What minimum bullet speed would be required for the board to swing all the way over after impact?
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