Physics

a spotlight on the ground shines on a wall 12 m away. if a man 2 m tall walks from the spotlight toward the building at a speed of 2.1 m/s, how fast (in m/s) is the length of his shadow on the building decreasing when he is 4 m from the building? (round your answer to one decimal place.)
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the wavelengths for visible light rays correspond to which of these options? a. about the size of a pen b. about the size of a virus or a large molecule
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In deep space, there is very little friction. Once they launch a probe into deep space, where there are no external forces acting on it, scientists shut the probes engines off because the scientists want the probe tostop immediately.speed up.slow down.move at constant velocity.
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a value of mass is given as 14.6 g to 15.2 g. a value of volume is given as 2.4 to 2.8 m3. state the density using reasonable outer limits.
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Sound travels through air at a speed of 342m/s342m/s at room temperature. What is the frequency of a sound wave with a wavelength of 1.8m1.8m
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Two spheres of masses 200kg and 100kg respectively have the centres seperated by a distance of 0.5m. Calculade the magnitude of force of attraction between them. G = 67x 10" N m kg -
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why does it take more energy to convert liquid water to steam than it does to convert ice to liquid water
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as the dyes get longer, two effects compete. equation (5) indicates that as n; increases, the absorption wavelength should decrease, but as l increases, the absorption wave length should increase which one wins? can you figure out why?
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Who discovered energy quanta and earned a Nobel Prize in Physics?
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if the speed of the suitcase is zero at the bottom of the ramp, what is its speed after it has traveled 3.80 m m along the ramp?
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a television picture tube accelerates electrons through a potential difference of 30,000 v. find the minimum wavelength
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a ball rolling down a hill accelerates from 40 m/sec to 60 m/sec in 3 seconds. what is the ball's acceleration?
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Two aircraft are flying toward each other at the same speed. They each emit a 800 HZ whine. what speed (km/hr) must each aircraft have an order that pitch they both hear is 2 times the emitted frequency. Hint: the speed of sound is 343m/s
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What is the force on a 1 000 kilogram-elevator that is falling freely under the acceleration ofgravity only (9.8m/s)?
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the source that creates an excess of electrons (negative charge) at one end of a conductor and a deficiency of electrons (positive charge) at the opposite end represents the
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Which reaction illustrates conservation of mass? A. 2 Cu + O2 2 CuO B. Fe + H2O Fe3O4 + H2 C. CH4 + Br2 CBr4 + HBr
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in 1959, the water stored behind hegben lake dam in montana began to slosh violently back and forth in a series of oscillating waves. these seiches were caused by
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A 65-kilogram student travels down a staircase that is 12 meters high. What is thegravitational potential energy of the student after traveling 5.0 meters?
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what is the relationship between weight and best range airspeed (vbr) and best endurance airspeed (vbe)?
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g which of the following wavelengths of light is most likely to cause a sunburn? explain your answer. a. 700 nm b. 400 nm c. 200 nm
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tarzan grabs a vine hanging vertically from a tall tree when he is unning horizontally at 9.0m/s. how high can he swing upward
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a 4n soccer ball sits motionless on a field. a player's foot exerts a force of 5n on the ball for a distance of 0.1 m, and the ball rolls a distance of 10m. how much kinetic energy does the ball gain from the player?
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a ball is thrown vertically upward from a height of 4 feet with an initial velocity of 50 feet per second. how high will the ball go?
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a 110-v hair dryer is rated at 1200 w. what current will it draw? select one: a. 12 a b. 0.090 a c. 11 a d. 5.0 a e. 1.0 a
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