The sound from a busy highway contains a 500 Hz Fourier component whose power at the highway is 1.5 ✕ 10−6 watt/m. (Ignore sound interactions with the ground).
(a)What are the sound intensity (in W/m2), the sound intensity level (in dB) and the loudness (in phon) of that Fourier component at a distance of 25 m from the highway?
intensity=? W/m2
intensity level =? dB
loudness=? phon
(b)What are the sound intensity (in W/m2), the sound intensity level (in dB) and the loudness (in phon) of that Fourier component at a distance of 50 m from the highway?
intensity=? W/m2
intensity level=? dB
loudness=? phon
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A package of mass 50 kg sits on an airless asteroid of mass 1.25 x 10^13 kg and radius 1000 m. We want to launch the package straight up so that it reaches a maximum distance of 4000 m from the center of the asteroid, where it will be picked up by a waiting ship before it can fall back down. We have a powerful spring whose stiffness is 1000 N/m. How much must we compress the spring to release it with the energy needed to reach the required altitude?
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A 8.50 kg mass is attached to the end of a hanging spring and stretches it 28.0 cm. It is then pulled down an additional 12.0 cm and then let go. What is the maximum acceleration of the mass? At what position does this occur? What is the position and velocity of the mass 0.63 s after release?
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A balance and torque experiment is conducted with an UN-balanced ruler.
Length of the ruler: 1 m
Mass of the ruler: 149 g
The pivot is at the 32-cm mark.
A 77-g mass is located at the 24-cm mark of the ruler.
We want to balance the ruler by placing another mass at the 11-cm mark.
What should be magnitude of this additional mass?
A balance and torque experiment is conducted with an UN-balanced ruler.
Length of the ruler: 1 m
Mass of the ruler: 97 g
The pivot is at the 61-cm mark.
A 45-g mass is located at the 33-cm mark of the ruler.
We want to balance the ruler by placing a 207-g mass somewhere on the ruler.
At which mark on the ruler should we place the 207-g mass?
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you have preparing your coffee in the morning. it comes out of the brewrt at a whopping 100c and you pour about 3kg of coffee. you then add in 1kg of cream at 15c to customize your taste and 1 ice cube with mass of 0.05kg at 0c. if we can assume both the cream and coffee behave like water, what will be the final temperature of your coffee mixture?
(let coffee= 1, cream=2, ice cube=3)
Question: calculate the final equilibrium temperature.
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Define each of the following reaction mechanism, giving its distinguishing characteristics
a) direct reaction; b) compound nucleus reaction; c) pre-equilibrium reaction; d) heavy-ion reaction, e) Stripping reaction f)Resonance and in each case give an example of the nuclear reaction described.
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A Car weighs 4900 N, and can accelerate from 0 to 72 km/hour in 5 seconds
What is the acceleration?
How large is the net force acting on the car?
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When three soap bubbles touch, the larger is inflated by the smaller until they form a single bubble. (a) What is the gauge pressure inside a soap bubble with a 1.50-cm radius? (b) Inside a 2.50-cm-radius soap bubble? (c) Inside a 3.75-cm-radius soap bubble? (d) Inside the single bubble they form if no air is lost when they touch?
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Consider the delta function potential well :V(x) = −αδ(x) (α > 0).
(a) What are the boundary conditions on the bound state wave function and its derivative at x = ±∞ and x = 0? Explain. Hint: You may find the property stated in Prob. 2 useful.
(b) Show that there is only one bound state.
(c) Find the energy E and wave function ψ(x) of the bound state.
(d) Find the transmission coefficient for scattering states, with energy E > 0 and incident form the left
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Why is the emission frequency lower than the excitation? What happens to the difference in energy?
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You are in Denver, which is 5,280 ft above sea level. Compare the acceleration due to gravity in Denver to that at sea level (h = 0). What are your Weight and your mass at each of these locations? Rearth = 6.371 x 10^6 m. Mearth = 5.9763 x 10^24 kg
a) list the given
b) List what you are trying to find
c) what equations will you use? List below
d) calculate the accelerations due to gravity for each location ( report your answer to 3 decimal places)
e) compare these accelerations (make a ration of the two to see the relationship)
f) calculate your mass (in kg) and your weight (in newtons) for both locations
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John’s mass is 98.6 kg, and Barbara’s is 67.0 kg. He is standing on the x axis at xJ = +9.45 m, while she is standing on the x axis at xB = +4.39 m. They switch positions. How far and in which direction does their center of mass move as a result of the switch?
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Problem: Car 1 (1000 kg) is traveling east at 8.0 m/s. Car 2 (2500 kg) is traveling west at 4.5 m/s. These two cars have a head-on collision. Car 2 recoils at 2.0 m/s.
a) what is given/known?
b) What is the linear momentum of Car 1 BEFORE the collision?
c) What is the linear momentum of Car 2 BEFORE the collision?
d) What is the linear momentum of the system ( car 1 and car 2) BEFORE the collision:
e) What is the linear momentum of the system (car 1 and car 2) AFTER the collision:
f) What is the linear momentum of Car 2 AFTER the collision:
g) What is the linear momentum of Car 1 AFTER the collision:
h) What is the velocity of car 1 after the collision?
i) is linear momentum of the system conserved in this collision?
j) is the kinetic energy of the system conserved in this collision? (show this by finding the kinetic energy before and after the collision)
k) What type of collision is this? How can you tell?
L) what is the change in the linear momentum of car 1 (a.k.a. the impulse)
m) what is the change in the linear momentum of car 2
n) if the contact time between the cars during the collision is 0.35 s, what is the average force experienced by car 1 on car 2?
o)if the contact time between the cars during the collision is 0.35 s, what is the average force experienced by car 2 on car 1?
p) compare the average forces and impulse values for car 1 and car 2 (e.g. divide average F for car 1 by average f for car 2)
q) Which of newtons laws is demonstrated by these comparisons above?
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1.Consider a satellite of the earth in a circular orbit of radius R. Let M and m be the mass of the earth and that of the satellite, respectively. Show that the centripetal acceleration of the satellite is aR = -(v^2/R)*(r/r) where v = |v| is the magnitude of the velocity V and r/r is a unit vector in the radial direction.
2.Using Newton's second low of motion and the law of universal gravitation, determine the speed v=|V| and the angular speed w for the circular orbit.
3.For two satellites in two different circular orbits with radii R1 and R2, respectively, prove kepler's second and third laws for this special case.
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Provide the rationale for the use of thermal remote sensing in water pollution detection.
Present the advantage of Forward-Looking Infrared (FLIR) systems.
Why can SAR imagery be used for the detection of oil spill in the sea surface?
Provide the rationale for SAR imagery be used in the estimation of sea surface salinity.
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