Suppose that you have obtained spectra of several galaxies and have measured the observed wavelength of the H-alpha line (rest wavelength = 656.3nm) to be:
Galaxy 1: 659 nm. Galaxy 2: 666.5 nm. Galaxy 3: 676.6 nm.
10. [4pt] Calculate the redshift, z, for each of these galaxies.
11. [4pt] Calculate the radial velocity of each of these galaxies.
12. [4pt] Assuming a Hubble Constant of 69.6 km/s/Mpc, cal- culate the distance to each of these galaxies (answer in Mpc).
In: Physics
Summarize the Source-Filter Theory. Be sure to incorporate glottal spectrum, resonance, bandpass filter, variable resonator, and the three functions.
In: Physics
a) Consider 1.3 moles of an ideal gas at an initial temperature of 400 K and in a 1.2 m3 closed container. If the gas goes through an isochoric process to twice the initial temperature, what is the new pressure of the gas in Pa?
b) Consider 1.3 moles of an ideal gas at an initial temperature of 400 K and in a 1.2 m3closed container. If the gas goes through an isothermal process to 3.6 m3, what is the new pressure of the gas in Pa?
c) Consider 1.3 moles of an ideal gas at an initial temperature of 400 K and in a 1.2 m3 closed container. If the gas goes through an isobaric process to 3.6 m3, what is the new temperature of the gas in Kelvin?
In: Physics
Photolithograph or e-beam lithography is known as a top-down approach to nanostructures while chemical synthesis is known as a bottom-up approach to nanostructures. Compare the advantages and disadvantages of these two different approaches in terms of a. cost, b. capital investment, c. control, d. precision, e. volume of production, and f. diversity of materials.
In: Physics
Estimate how often stars collide in the Milky Way (using the model of a cylinder with radius = disc scale length and height = 2* disc scale height)
In: Physics
Estimate how often galaxies collide in a galaxy cluster, i.e., the stellar component of one galaxy passing through another.(Model the average galaxy as a sphere with a radius of 10 kpc).
In: Physics
A 200 g hockey puck is launched up a metal ramp that is inclined
at a 30° angle. The coefficients
of static and kinetic friction between the hockey puck and the
metal ramp are #5 = 0.40 and pk =
0.30, respectively. The puck's initial speed is 14.9 m/s. What
speed does it have when it slides back
down to its starting point?
In: Physics
questions 1) : How to control the polarization of light and intensity and phase of light ????
questions 2) : How to control the polarization, intensity, phase of liquid crystal ???
In: Physics
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.
In: Physics
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?
In: Physics
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
In: Physics
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?
In: Physics