A 50 kg person jumps from a window ledge 4m above the pavement. A) How fast is
he going when he hits the ground? B) What impulse acts on the person's legs as he
strikes the ground? C) If the time of interaction is .06s how much force is acting?

What is an aquifer for science class

Arefrigerator uses r-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle except for the compression process. the refrigerant enters the evaporator at 120 kpa with a quality of 34 percent and leaves the compressor at 70°c. if the compressor consumes 450 w of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the cop of the refrigerator. (0.00644 kg/s, 800 kpa, 2.03)

How do you know how many valence electrons an atom has?