Matthew and his dad are walking along the beach. Matthew runs toward the water and dips his hands in the cool ocean. Then, he walks back to his dad and grabs his hand. “Matthew, your hands are so cold now!” his dad exclaims. Where did conduction occur during this scenario? A. between Matthew’s warmer body and his now cooler hand
B. between Matthew’s hand and his father’s hand
C. between Matthew’s warm hand and the cool water
D. between Matthew's father's hand and the cooler water

4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)

Talia is manufacturing rolls of wire for hanging pictures. she needs a material that is so that it can easily be pulled into wire without breaking.

If state law mandates that elevators cannot accelerate more than 2.40 m/s2 or travel faster than 14.8 m/s , what is the minimum time in which an elevator can travel the 373 m from the ground floor to the observatory floor? ?