Why are kinetic energy and the total force added to find the work done or the friction between the object and the ground?

6–55 refrigerant-134a enters the condenser of a residential heat pump at 800 kpa and 358c at a rate of 0.018 kg/s and leaves at 800 kpa as a saturated liquid. if the compressor consumes 1.2 kw of power, determine (a) the cop of the heat pump and (b) the rate of heat absorption from the outside air.

Which is not true about oxygen-17 and oxygen-18?

Acar drives toward the right over the top of a hill, as shown below. which arrow represents the centripetal acceleration? w x y z