Aloaded ore car has a mass of 950 kg and rolls on rails with negligible friction. it starts from rest and is pulled up a mine shaft by a cable connected to a winch. the shaft is inclined at 30.08 above the horizontal. the car accelerates uniformly to a speed of 2.20 m/s in 12.0 s and then continues at constant speed. (a) what power must the winch motor provide when the car is moving at constant speed? (b) what maximum power must the winch motor provide? (c) what total energy has transferred out of the motor by work by the time the car moves off the end of the track, which is of length 1 250 m?

1. what is the relationship between wavelength and the penetrating power of an electromagnetic wave? a) the penetrating power has no relationship to the wavelength. b) the penetrating power increases as the wavelength increases. c) the penetrating power decreases as the wavelength increases. d) the penetrating power decreases as the wavelength decreases. 2. as ice melts and turns into water, the speed of sound through the material would most likely do what? justify your answer. a) the speed would not change because the material is always water. b) the speed of sound would increase because the density of water is less than that of ice. c) the speed of sound would increase because energy is added to ice in order to make it melt. d) the speed of sound would decrease because sound travels faster through solids than liquids. 3.which of these waves need a medium to travel through? a) sound b) x-rays c) infrared rays d) visible light