The fastest roller skater skated over 402 m, reaching a final velocity of 20.5 m/s. Suppose this roller skater has a mass of 61.4 kg. What is the total change in the internal energy of the skates, wheels, and ground as the skater skates past the finish line?The fastest roller skater skated over 402 m, reaching a final velocity of 20.5 m/s. Suppose this roller skater has a mass of 61.4 kg. What is the total change in the internal energy of the skates, wheels, and ground as the skater skates past the finish line?

Unpolarized light falls on two polarizer sheets whose transmission axes are at right angles. a third polarizer is placed between the first two so that its axis makes a 52-degree angle with the axis of the first polarizer. a) what fraction of the incident light intensity is transmitted through the first polaroid? b) what fraction of the incident light intensity is transmitted through the second polaroid? c) what is the angle of polarization of the light that enters the third polaroid? d) what fraction of the incident light intensity is transmitted through the third polaroid. e) what happens if the middle polaroid is removed?

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Aplane flying horizontally at an altitude of 1 mile and a speed of of 500mih passes directly over a radar station. find the rate at which the distance from the plane to the station is increasing when it is 2mi away from the station.