Question 5 0.77 pts Aleia has a water bottle whose water has gotten pretty warm. She drops ten 13 C ice cubes of edge length 13 mm in the water to cool it down. Ultimately the ice melts into water and comes to equilibrium with the surrounding water in the bottle at 50 F. The whole process leading to this equilibrium state takes 10 min. At what rate in watts is heat flowing to the ice as it melts and then ultimately warms up and comes to equilibrium with the water in the bottle? We assume for simplicity that this rate remains constant throughout all the processes described. The density of ice is about 917 kg/m?. Note that the specific heat of ice is 2090 J/ (kg K), the latent heat of fusion of water is 334, 000 J /kg, and the specific heat of liquid water is 41843/ (kg K). 13.501 Question 6 0.77 pts Two speakers are 1.5 m apart. The speakers both emit precisely the same pure tone in all directions (i.e. same frequency, same amplitude, and emitted with same phase). Jason is standing on the line joining the two speakers to one side of both of them, and he hears no sound. As the frequency of both speakers is slowly doubled, Jason hears the sound go through the sequence loud-silent-loud-silent-loud. What was the original sound frequency in Hz? Assume the standard speed of sound. 57.17 Question 7 0.77 pts Fresh concrete for use in construction is typically heated to improve setting and strength development. A typical way to do this is the heat the water that's mixed in with the concrete, and doing this requires some sort of water heating system. Jack has built a concrete plant, and he's decided to try a heat pump boiler system for his water heating needs to save on energy costs and reduce carbon emissions. His boiler maintains about 10, 000 gallons of water at around 129F. The heat pump system gets its input heat from the soil deep underground because the temperature of this soil remains pretty stable even in cold weather. In fact, the soil temperature in his system is always around 58F. The boiler takes thermal energy out of the soil at a rate of 48 kW. While heating the water in the tank, the water heater uses electrical energv at a rate of about 30 kW. At what bercent of its theoretical maximum coefficient of performance is the water heater onerating? Question 7 0.77 pts Fresh concrete for use in construction is typically heated to improve setting and strength development. A typical way to do this is the heat the water that's mixed in with the concrete, and doing this requires some sort of water heating system. Jack has built a concrete plant, and he's decided to try a heat pump boiler system for his water heating needs to save on energy costs and reduce carbon emissions. His boiler maintains about 10, 000 gallons of water at around 129F. The heat pump system gets its input heat from the soil deep underground because the temperature of this soil remains pretty stable even in cold weather. In fact, the soil temperature in his system is always around 58F. The hoiler takes thermal energy out of the soil at a rate of 48 kKW. While heating the water in the tank, the water heater uses electrical energy at a rate of about 30 kW. At what percent of its theoretical maximum coefficient of performance is the water heater operating? 62.5