solve & explain please
If an electron is accelerated from 2 mm/s through a potential difference of 500 V between two parallel plates separated by a distance of 2.0 cm. What is the speed of the electron?
In: Physics
A 12,000 N car starts from rest and rolls down a hill from a height of 10.0 m (see figure). It then moves across a level surface and collides with a light spring-loaded guardrail.
(a) Neglecting any losses due to friction, and ignoring the
rotational kinetic energy of the wheels, find the maximum distance
the spring is compressed. Assume a spring constant of
1.2 106 N/m.
? m
(b) Calculate the maximum acceleration of the car after contact
with the spring, assuming no frictional losses.
? m/s2
(c) If the spring is compressed by only 0.30 m, find the change in
the mechanical energy due to friction.
? J
In: Physics
In the figure, we must apply a force of magnitude 82.0 N to hold the block stationary at x = -2.00 cm. From that position, we then slowly move the block so that our force does +7.00 J of work on the spring–block system; the block is then again stationary. What are the block's positions? ((a) positive and (b) negative)
In: Physics
A proton in an atomic nucleus is bound to other protons and neutrons in the nucleus by the strong nuclear force when it is within approximately 3 fm of another particle. What is the approximate kinetic energy of a proton that is localized to such a region? What would be the corresponding energy of an electron localized to within such a region? Compare this to typical beta energies for beta decay. Is a release of electrons
In: Physics
A 50 kg teenager just got his license and is driving his brand new Escalade (mass 1100 kg) at 30 m/s. As he is texting and driving, he crashes into a stopped minivan, which has a mass of 980 kg. Since he is not wearing a seatbelt, he flies out of the window after the crash. If the Escalade and Minivan move together with a speed of 13 m/s after the perfectly elastic crash, with what velocity is the teenage (former) driver now flying through the air?
In: Physics
In this section we will study the problem of gender-wage discrimination. It is often argued that women are paid less than equally qualified men to do the same job. This is also true in academia. The University of Calgary administrators are trying to determine the gender earnings gap in order to `compensate' women who are underpaid. In the empirical analyses that follow, the following variables are defined as:
Y - Log earnings
F - female indicator
Age - age of individual
Assoc - indicator for Associate Professor Rank
Full - indicator for Full Professor Rank
ϴf- faculty/college indicators (e.g., Social Science, Engineering, Business...)
ϴd- department indicators (e.g., economics, history...)
E[Yi|Fi = 1] - E[Yi|Fi = 0]
Do you think that this identified the causal effect of being a woman on wage? Explain.
Yi = β0 + αFi + εi (1)
What variation in the data is being used to identify the male-female difference in earnings?
Yi = β0 + αFi + βAgei + εi (2)
How does adding age to the regression change the source of variation used in identifying the male-
female wage differential?
If female professors are, on average, younger than male professors, how would you expect the estimate of α to change from equation (1)?
Yi = β0 + αFi + βAgei + γ1Associ + γ1Fulli + εi (3)
Now what variation in the data is used to identify the male-female difference in earnings? How would the estimate of α change relative to equation (1) if females are over-represented in the assistant professor rank?
Yi = β0 + αFi + βAgei + γ1Associ + γ1Fulli + ϴf + εi (4)
Now what variation in the data is used to identify the male-female difference in earnings? How would the estimate of α change relative to question 2 if females are over-represented in the higher paying faculties/colleges? What is the difference between running this regression and running regression 3 separately for each faculty/college?
In: Physics
Which of the following statements are correct?
A. All oscillatory motion is Simple Harmonic Motion.
B. Simple Harmonic motion is a special case of oscillatory
motion.
C. Oscillatory motion is a special case of Simple Harmonic
motion.
D. Oscillatory motion cannot be Simple Harmonic motion
Which of the following statements is correct?
A. In simple harmonic motion, kinetic energy is constant.
B. In simple harmonic motion, potential energy is constant.
C. In simple harmonic motion, the sum of kinetic and potential
energy is constant.
D. In simple harmonic motion, the difference between kinetic and
potential energy is constant.
In: Physics
Two blocks connected by a string are pushed across a horizontalisurface by a force applied to one of the blocks as, shown in the figure. The coefficient of kinetic friction between the blocks and the surface is 0.20. If, F 20 N and M1.5 kg, what is the tension in the connecting, string?
In: Physics
Monica and Dylan are doing a “thought experiment”. They are imagining that Monica is in a space ship orbiting a black hole, just outside the event horizon, while Dylan is in a space ship 1 light year away. Monica and Dylan each send each other a signal using a laser. From each of their perspectives, their laser flashes once a second. To Dylan, is Monica’s laser flashing faster, slower or at the same rate (once a second)? Similarly, how fast does Dylan’s laser appear to be flashing from Monica’s point of view?
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An electrically neutral penny is charged by induction to +5.5 LaTeX: \muμC. After charging, is the penny now more massive or less massive, and what is its change in mass? Group of answer choices
More massive, 3.4E13 kg
Less massive, 3.1E-17 kg
More massive, 3.1E-17 kg
Less massive, 3.4E13 kg
More massive, 3.1E-12 kg
In: Physics
a) How is charge transferred in the process of friction?
b) How is charge transferred in the process of direct contact?
c) How is charge transferred in the process of inductance?
d) How can a charged object attract a neutral object?
Please type your responses.
In: Physics
Two air track gliders of mass 400.0 g and 300.0 g are moving towards each other in opposite directions with speeds of 60.0 cm/s and 100.0 cm/s, respectively. Take the direction of the more massive glider as positive. Use units of "g" and "cm/s" in your calculations.
In: Physics
Question 1 Part A
If at a certain point in time the displacement is positive for an object moving under simple harmonic motion, what is the sign of its acceleration?
A. |
Depends if the object is moving positively or negatively. |
|
B. |
Can not be determined. |
|
C. |
Positive. |
|
D. |
Negative. |
Part B
For an object in simple harmonic motion, what is the length of time required to return to its original position and to be traveling in the original direction?
A. |
The period, T. |
|
B. |
The frequency, f. |
|
C. |
The frequency, T. |
|
D. |
The period, f. |
Part C
For an object moving under simple harmonic motion while attached to a spring, when is the speed the greatest?
A. |
When there is maximum displacement from equilibrium . |
|
B. |
When there is no displacement from equilibrium . |
|
C. |
When the velocity is a minimum. |
|
D. |
Only when the object on the spring is not hanging down due to gravity. |
Part D
A spring is hanging motionless from the ceiling of a room on the earth. You attach a mass to the end of the spring and after releasing the mass, you observe that the spring extends a distance before momentarily coming to a halt. What then must be the distance below just the spring's equilibrium position to the new equilibrium position of the spring-mass system?
A. | ||
B. | ||
C. | ||
D. |
Part E
A block is attached to a spring and is hanging downward motionless from the ceiling of a room on the earth. Is the spring in equilibrium?
A. |
No. |
|
B. |
Unable to determine without more information. |
|
C. |
Yes. |
|
D. |
We need to know the mass of the block. |
Part F
For an object moving under simple harmonic motion while attached to a spring, when is the net force zero?
A. |
Only when the object on the spring is not hanging down due to gravity. |
|
B. |
When there is maximum displacement from equilibrium. |
|
C. |
When the velocity is a minimum. |
|
D. |
When there is no displacement from equilibrium. |
Part G
What is the term for the object's maximum possible displacement when moving under simple harmonic motion?
A. |
There is no term for this situation. |
|
B. |
Amplitude of displacement. |
|
C. |
Amplitude of velocity. |
|
D. |
Amplitude of acceleration. |
Part H
A spring is hanging downward from the ceiling of a room on the earth, has nothing attached to the end, and is motionless. Is the spring in equilibrium?
A. |
Unable to determine without more information. |
|
B. |
No. |
|
C. |
Yes. |
|
D. |
There must be a mass on the end of the spring. |
Part I
For an object moving under simple harmonic motion while attached to a spring, when is the speed zero?
A. |
Only when the object on the spring is not hanging down due to gravity. |
|
B. |
When there is no displacement from equilibrium. |
|
C. |
When there is maximum displacement from equilibrium. |
|
D. |
When the velocity is a maximum. |
Part J
For an object moving under simple harmonic motion while attached to a spring, when is the net force the greatest?
A. |
When there is no displacement from equilibrium. |
|
B. |
When the velocity is a maximum. |
|
C. |
Only when the object on the spring is not hanging down due to gravity. |
|
D. |
When there is maximum displacement from equilibrium. |
In: Physics
In an (AC) RLC circuit, does the what is the order of obstruction? Does the inductor, capacitor, or resistor obstruct first? and last? And what are each of them obstructing ( change of current or change of voltage)?
What about in (DC) source?
What happens when the capacitor receives a change in rate of voltage? Does it induce a new current to push back the voltage? I am very confused.
Please show in detail and diagrams.
Thank you
In: Physics
if a galaxy is tilted 45 degrees to my line of sight then how much does the wavelength of 21 cm shift when you move from the center to the edge of galaxy given a orbital speed of 220 km/s?
In: Physics