Think of a Newtonian cradle made of only two marbles. These two marbles of masses m1 and m2 are each suspended by identical strings. The strings are initially both vertical so the marbles are touching each other when undisturbed. The marble with m1 is shifted away from the initial position until is reaching the height h1 while the length of the string does not change and then is set free to fall and collide with marble m2. What is the formula for the height which both marbles will reach after the collision if: a). The collision is elastic; b). The collision is inelastic; (c). What will be the heat developed during the collision in both cases?Hint: when the marbles collide, all vectors velocity are orientated along the same axis.
In: Physics
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The intensity of a sound decreases by a factor of 4. As a result, the sound intensity level decreases by ______. |
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The human threshold of pain is about how many decibels? |
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Two sinusoidal sound waves with slightly different frequencies combine to form a third sound wave called a beat. How does the amplitude of the beat change over time, or does it remain constant? |
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Two audio speakers produce, in step, the same sinusoidal sound of wavelength λ. A listening device is positioned at point Q in the room and registers no sound from the speakers. What characterizes the two sound waves as they arrive at point Q? Assume the room is anechoic (produces no echoes.) |
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At an auto race, a member of the pit crew stands beside the track. A car approaches him at 110 m/s and emits a sound at frequency 1200 Hz. The air is still and the speed of sound is 340m/s. What frequency will the pit crew member hear? |
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The frequency of the faintest audible sound is about 1,000 Hz. What is the pressure variation corresponding to this sound? |
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Two loudspeakers are placed 4.5 m apart. They produce the same sounds, in step, across a frequency range of 744 Hz to 992Hz Point P is located 5.30m from one loudspeaker and 3.60m from the other. What frequency of sound from the two speakers will produce destructive interference at point P? Assume the speed of sound is 344m/s |
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Two loudspeakers are placed 6.0 m apart. They produce the same sounds, in step, across a frequency range of 252Hz to 665Hz Point P is located 5.10m from one loudspeaker and 3.60m from the other. What frequency of sound from the two speakers will produce constructive interference at point P? Assume the speed of sound is 344m/s |
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In: Physics
In: Physics
Needs to document an amusement park ride. For example: Round
rotating cylinder where the floor drops out. The information can
come from any online website. Needs to know the radius and speed at
which the ride needs to rotate so that you don't fall?
Calculate the coefficient of static friction for this ride
also
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Aliens are observing a park in new york. They notice a merry-go-round has a radius of 3.12m and a moment of inertia of 3100kgm^2 at the vertical axis through the center. The contraption has been lubricated recently so there is no friction. one of the earthlings applies a tangential force of 19N for 13s begging at rest. Unfortunaley after gathering this data the aliens computer broke so now they must calculate the work that was done over the course of the 13s.
In: Physics
A bullet of mass m = 8.00 g is fired into a block of mass M = 210 g that is initially at rest at the edge of a table of height h = 1.00 m (see figure below). The bullet remains in the block, and after the impact the block lands d = 1.90 m from the bottom of the table. Determine the initial speed of the bullet.
________m/s
In: Physics
Which pair of quantities represent scalar
quantities?
(1) displacement and velocity
(2) displacement and time
(3) energy and velocity
(4) energy and time
In: Physics
You are on roller blades, holding a rope attached to a truck. Starting from rest, the truck pulls you. After traveling for 7.33 s, you are moving at 10.0 m/s. If the friction in your roller blades is negligible, what is the tension in the rope? Your mass is 69.0 kg. Report your answer in SI units, rounded to the nearest whole number.
In: Physics
In: Physics
Radiation from the Sun reaching Earth (just outside the atmosphere) has an intensity of 1.35 kW/m2. (a) Assuming that Earth (and its atmosphere) behaves like a flat disk perpendicular to the Sun's rays and that all the incident energy is absorbed, calculate the force on Earth due to radiation pressure. (b) For comparison, calculate the force due to the Sun's gravitational attraction. Assume that the speed of light and Earth radius are 2.998 × 108 m/s and 6.37 thousand km respectively.
In: Physics
Consider a single pane glass window that has an area of 8ft^2 and is 3/16” thick. The outside temperature is -10oC and the inside temperature is 21oC. [9]
a.How much heat flows through the window in 8 hours? Use an R-value.
b. In reality, all surfaces have a thin layer of air covering them that does not move. This air“film” is about .0005m thick. Calculate how much heat flows through the window in the 8 hour period with the addition of this film of air on both sides of the window
Most windows are double-pane glass with ½” Argon gas between the two panes. If the R-value of Argon gas is 0.54 W^-1 •m2•oC for a thickness of 1 cm, find:
i.The effective RSI-value of the window.
ii.The effective R-value of the window.
iii.The effective U -value of the window
In: Physics
A horizontal beam of length 4.07 m and weight 150 N is attached to a vertical wall at a right angle. There is also a support wire of length 5.01 m which attaches the far end of the beam to the wall from above. Off of the far end of the beam also hangs an object of weight 290 N.
A) What is the magnitude of the tension in the support wire?
B) What is the horizontal component of the force exerted on the beam at the wall?
C) What is the vertical component of the force exerted on the beam at the wall?
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How much horsepower is needed, in a vehicle described below, to travel a distance of 1 statute mile in 35 seconds, from a standing start, with the following information:
Air density @ sea level, 59 degrees, no wind = p = .002377 slugs/ft^3
Coefficient of drag (flat plate, NASA) = C(d) = 1.28
Weight = W = 4451 lbs
Area = A = 197.5" long x 78.2" wide x (1 ft^2/ 144 in^2) ( Size of vehicle)
In: Physics
An object starts at the position 4.8x̂ + -9.7ŷ m, with an initial velocity of 1.5x̂ + -4.4ŷ m/s. It has an acceleration of -0.152x̂ + 0.686ŷ m/s2. After 2.31 s, what is its speed? Report your result in SI units, rounded to one decimal place.
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In: Physics