10) On a frozen lake, the ice will break if the pressure on it is greater than 1.0 Pa. Four boys stand on the ice. Which one will fall through? *
A) Weight of boy = 200N, area of his feet = 0.027m^2
B) Weight of boy = 300N, area of his feet = 0.025m^2
C) Weight of boy = 400N, area of his feet = 0.050m^2
D) Weight of boy = 500N, area of his feet = 0.056m^2​

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)

Atruck driver is attempting to deliver some furniture. first, he travels 8 km east, and then he turns around and travels 3 km west. finally, he turns again and travels 13 km to his destination. what is the drivers distance

Which of the following is a measure of the amount of light a star directly emits?               a.  luminosity    b.  intensity    c.  wavelength    d.  brightness