Physics

A star much cooler than the sun would appear (a) red; (b) blue; (c) smaller; (d) larger.
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Krista is playing tennis at the park. When the tennis ball flies toward her, Krista hits the ball with her racket, which causes the ball to fly in the opposite direction. According to Newton's third law of motion, which of the following is true?A. When the racket hits the tennis ball with a force, the ball does not apply any reaction force to the racket.B. When the racket hits the tennis ball with a force, the tennis ball applies an equal but opposite force to the racket.C. When the racket hits the tennis ball with a force, the ball applies a much weaker force in the opposite direction of the racket's force.D. When the racket hits the tennis ball with a force, the ball applies an equal force in the same direction as the racket's force.
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Calculate the force of gravity on a 5 kg mass at Earth's surface. The mass of the Earth is 6 x 1024 kg and its radius is6.4 x 106 m. Do not use scientific notation. Round to a whole number (no decimal).
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The wavelength of green light is about the size of an atom. (T/F)
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The thermal conductivity of a sheet of rigid insulation is reported to be 0.029 W/(mK). The temperature difference across a 20 mm thick sheet of insulation is 10C. (a) What is the heat flux through a 2m x 2m sheet of this insulation? (b) What is the total rate of heat transfer through the sheet?
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A block with a mass of 8.7 kg is dropped from rest from a height of 8.7 m, and remains at rest after hitting the ground. 1)If we consider the system to consist of the block, the ground, and the surrounding air, what is the change in the internal energy of the system
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do you think toxicity is a qualitative or quantitative property? explain
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A small pumpkin is launched from a very versatile catapult at a variety of speeds and angles. The angles are measured relative to the horizontal. Rank each of the following trials by the maximum height reached by the pumpkin. (1=highest) Consider air resistance to be negligible.1 2 3 4 Speed: 30.7m/s, Angle: 35.71 2 3 4 Speed: 47.9m/s, Angle: 33.21 2 3 4 Speed: 21.8m/s, Angle: 67.71 2 3 4 Speed: 7.7m/s, Angle: 62.1
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A model of a helicopter rotor has four blades, each of length 3.0 m from the central shaft to the blade tip. The model is rotated in a wind tunnel at a rotational speed of 560 rev/min.part A :What is the linear speed of the bladetip?part B :What is the radial acceleration of the bladetip expressed as a multiple of the acceleration of gravity,g?
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The energy released by the exploding gunpowder in a cannon propels the cannonball forward. Simultaneously, the cannon recoils. The mass of the cannonball is less than that of the cannon. Which has the greater kinetic energy, the launched cannonball or the recoiled cannon? Assume that momentum conservation applies.
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What is the freezing point of an aqueous solution that boils at 101 degrees C? Kfp = 1.86 K/m and Kbp = 0.512 K/m. Enter your answer to 2 decimal places.
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An iron block with mass mB slides down a frictionless hill of height H. At the base of the hill, it collides with and sticks to a magnet with mass mM.Now assume that the two masses continue to move at the speed v from Part A until they encounter a rough surface. The coefficient of friction between the masses and the surface is . If the blocks come to rest after a distance s, which of the following equations would you use to find s?View Available Hint(s)Now assume that the two masses continue to move at the speed from Part A until they encounter a rough surface. The coefficient of friction between the masses and the surface is . If the blocks come to rest after a distance , which of the following equations would you use to find ?((mB)2mB+mM)gH=mBgs((mB)2mB+mM)gH=mMgs((mB)2mB+mM)gH=(mB+mM)gs((mB)2mB+mM)gH=(mB+mM)gs((mB)2mB+mM)gH=(mB+mM)g
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A muon has a rest mass energy of 105.7 MeV, and it decays into an electron and a massless particle. If all the lost mass is converted into the electrons kinetic energy, what is the electrons velocity?
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which is is not an effective way to gain fitness
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A firefighting crew uses a water cannon that shoots water at 25.0 m/s at a fixed angle of 53.0 above the horizontal. The fire-fighters want to direct the water at a blaze that is 10.0 m above ground level. How far from the building should they position their cannon? There are two possibilities; can you get them both? (Hint: Start with a sketch showing the trajectory of the water.)
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Two uncharged metal balls, Y and X, each stand on a glass rod and are touching. A third ball carrying a negative charge, is brought near the first two While the positions of these balls are fixed, ball Y is connected to ground. Then the ground wire is disconnected. While Y and X remain in touch, the ball carring the negative charge is removed. Then ball Y and X are separated.
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If the plane is flying in a horizontal path at an altitude of 98.0 m above the ground and with a speed of 73.0 m/s, at what horizontal distance from the target should the pilot release the canister? Ignore air resistance.
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The average speed of a train is 24.0km/hr. Suppose a train moving at this speed accelerates -0.20 m/s^2 until it reaches a speed of 8.0 km/hr. How long does it take the train to undergo this change in speed?
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Roberta's next door neighbor has a theory that the best time to wash your car is late in the afternoon on Sunday. Is this a scientific theory? A. No, it is an opinion and is not testable. B. Yes, the car will stay clean for more of the week. C. Yes, the neighbor might be a scientist. D. No, it is better to wash cars on Saturday.
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A bullet is fired from a rifle that is held 1.60 m above the ground in a horizontal position. The initial speed of the bullet is 1058 m/s. Calculate the time it takes for the bullet to strike the ground.
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If two identical conducting spheres are in contact, any excess charge will be evenly distributed between the two. Three identical metal spheres are labeled AA, BB, and CC. Initially, AA has charge qq, BB has charge q/2q/2, and CC is uncharged.
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The efficiency of a squeaky pulley system is 73 percent. The pulleys are usedto raise a mass to a certain height. What force is exerted on the machine if arope is pulled 18.0 m in order to raise a 58 kg mass a height of 3.0 m
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What is the relationship between the amount of stretch or compression in an elastic object and the amount of force that is applied to that object?Applied force is one-half the amount of stretch or compression.They are directly proportional.They are inversely proportional.Applied force is double the amount of stretch or compression.
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According to the Stefan-Boltzmann law, how much energy is radiated into space per unit time by each square meter of the Suns surface? If the Suns radius is 696,000 km, what is the total power output of the Sun?
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