Four identical charges (+2.0 ?C each) are brought from infinity and fixed to a straight line. The charges are located 0.40 m apart. Calculate the amount of work done in assembling the charges.
In: Physics
1) What are a Vande Graaf generator and a Tesla Coil? Why aren’t people hurt when they come in contact with such high voltage?
2) What is the difference between AC and DC? Three prong and two prong plugs? 110 and 220 plugs?
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A 2.25×104 N elevator is to be accelerated upward by connecting it to a counterweight using a light (but strong!) cable passing over a solid uniform disk-shaped pulley. There is no appreciable friction at the axle of the pulley, but its mass is 875 kg and it is 1.50 m in diameter.
How heavy should the counterweight be so that it will accelerate the elevator upward through 6.00 m in the first 4.00 s , starting from rest?
Under these conditions, what is the tension in the cable on elevator side of the pulley?
Under these conditions, what is the tension in the cable on counterweight side of the pulley?
I posted this before but 3000 wasnt the correct answer
In: Physics
Three point charges are arranged as follows: Charge Q1 = + 5.00 nC is located at the origin. Charge Q2 = -3.00 nC is located at x = +4.00 cm, y = 0 cm. Charge Q3 = + 6.00 nC is at x = 0 cm, y = -3.00 cm. a. What is the net electric field at point P with coordinates x = 4.00 cm, y = -3.00 cm?
(i) Express your answer as a vector in i, j, k notation.
(ii) Express your answer as the total magnitude and direction θ from the +x-axis. b. What is the net electric force on an proton placed at point P? Express your answer only in terms of magnitude and direction.
c. What is the acceleration of this proton? Express your answer only in terms of magnitude and direction. Mass of the proton is 1.673∙10-27 kg.
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A ball rolls down along an incline without slipping. A block slides
down from the same incline without friction. Assuming the two
objects start from the same position, which of the following
statement is correct?
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What starts a dislocation and how does this advance in a crystal structure?
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This question is about throwing a ball vertically upwards and catching the ball.
Compare the part of the graph of mechanical energy vs. time before the ball is in free-fall to the part while the ball is in free fall. Carefully explain, using the concept of work done on the system, why the ball’s mechanical energy changed as it did.
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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
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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.
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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
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Which pair of quantities represent scalar
quantities?
(1) displacement and velocity
(2) displacement and time
(3) energy and velocity
(4) energy and time
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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.
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