Physics

A model airplane with mass 0.750-kg is tethered by a wire so that it flies in a circle of radius 30.0-m. The airplane engine provides a force of 0.800-N perpendicular to the tethering wire. (Consider the airplane to be a point mass) (a) Find the torque that the net thrust produces about the center of the circle. (b) Find the angular acceleration of the airplane. (c) Find the linear acceleration of the airplane tangent to its flight path.
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Two balanced three-phase loads that are connected in parallel are fed by a three-phase line having a series impedance of (0.4+????2.7) per phase. One of the loads absorbs 560 kVA at 0.707 power factor lagging, and the other 132 kW at unity power factor. The line-to-line voltage at the load end of the line is 22003 V. Compute (a) the line-to-line voltage magnitude (in RMS value) at the source end of the line, (b) the total real and reactive power losses in the three-phase line, and (c) the total real and reactive power supplied at the sending end of the line.
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Consider a horizontal semi-transparent plate at a temperature 360 K that is irradiated from above and below. Air at [infinity] 310 K flows over both sides of the plate with a convective coefficient, 45 W/m2K. The absorptivity of the plate is 0.4. If the radiosity is 4500 W/m2, find the irradiation, in W/m2, and emissivity of the plate. Is the plate diffuse-gray?
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Whose view was that the Cosmos was based on the belief that every occurrence in the physical universe had logos behind it and that is where life originated?
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A rope vibrates every 0.5 s. What is the frequency of the waves? 5 Hz 2 Hz 0.5 Hz 1 Hz
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Elements in a period have _____________.Press enter to interact with the item, and press tab button or down arrow until reaching the Submit button once the item is selectedAThe same atomic radiusBSimilar chemical propertiesCThe same number of protonsDA wide range of chemical properties
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6) 100 ml of water is initially at 20C. 30,000 J of heat is added to the water. What is temperature change for the water?
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The energy of a photon is inversely proportional to the wavelength of the radiation. (T/F)
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An X-ray telescope located in Antarctica would not work well because of (a) the extreme cold; (b) the ozone hole; (c) continuous daylight; (d) Earths atmosphere.
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a car moved 60km east and 90km west in 25 seconds. what is the velocity
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2)It is known that the connecting rodS exerts on the crankBCa 2.5-kN force directed down andto the left along the centerline ofAB. Determine the moment of this force about for the two casesshown at below.
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Perform the following unit conversions: a. 1 L to in.3b. 650 J to Btuc. 0.135 kW to ft lbf/sd. 378 g/s to lb/mine. 304 kPa to lbf/in.2f. 55 m3/h to ft3/sg. 50 km/h to ft/sh. 8896 N to ton (=2000 lbf)
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Two small plastic spheres each have a mass of 1.2 g and a charge of -56.0 nC . They are placed 3.0 cm apart (center to center). Part A What is the magnitude of the electric force on each sphere? Express your answer to two significant figures and include the appropriate units.
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If you fire a projectile from the ground, it hits the ground some distance R away (called "the range"). If you keep the launch angle fixed, but double the initial launch speed, what happens to the range?
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A metal, M, forms an oxide having the formula MO2 containing 59.93% metal by mass. Determine the atomic weight in g/mole of the metal (M). Please provide your answer in 2 decimal places.
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4 PointsA car of mass 1300 kg drives in a circle of radius 85 m. If the car has a speedof 20 m/s, what is the centripetal force acting on the car?OA. 6118 NOB. 1300 NO C. 7982 NO D. 305.9 NSUBMIT
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A rectangular block floats in pure water with 0.400 in. above the surface and 1.60 in. below the surface. When placed in an aqueous solution, the block of material floats with 0.800 in. below the surface. Estimate the specific gravities of the block and the solution.
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A 3.0-kg block starts at rest at the top of a 37 incline, which is 5.0 m long. Its speed when it reaches the bottom is 2.0 m/s. What is the average friction force opposing its motion?
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To have a negative ion, you must have: A. added a positron to the outer electron shell. B. taken away a proton from the nucleus. C. added an electron to the outer electron shell. D. added a positron to the nucleus. E. None of these; only positive ions can exist in nature.
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For an object of mass m and acceleration a, which equation can be used tocalculate the applied force on the object?
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Two identical loudspeakers separated by distance dd emit 200 Hz sound waves along the x-axis. As you walk along the axis, away from the speakers, you don't hear anything even though both speakers are on. What are the three lowest possible values of d? Assume a sound speed of 340 m/s.
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Your electricity bill says 834-kWh of consumption. With this amount of energy, how many 59-W light bulbs can be powered for an average of 7 hours?
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An electrically neutral model airplane is flying in a horizontal circle on a 2.0-m guideline, which is nearly parallel to the ground. The line breaks when the kinetic energy of the plane is 50 J. Reconsider the same situation, except that now there is a point charge of q on the plane and a point charge of -q at the other end of the guideline. In this case, the line breaks when the kinetic energy of the plane is 53.5 J. Find the magnitude of the charges.
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A car is traveling at 33.0 m/s when the driver uses the brakes to slow down to 29.0 m/s in 2.50 seconds. How many meters will it travel during that time?
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