The velocity of an object with mass = 2kg is given as a function of time: V = 2ti + 4j

Find the force acting on the object at t = 2 seconds.

Natural forces that can alter ecosystems include seasons and climate changes. t or f

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)

Atoms seldom exist as independent particles in nature a) as single particles, most atoms have low potential energy b) their electronegativity is much lower when they combine with other atoms c) atoms are more stable when they combine with other atoms d) neutral particles are rare