Four charged particles are placed so that each particle is at the corner of a square. the sides of the square are 15 cm. the charge at the upper left corner is +3.0 ? c, the charge at the upper right corner is ? 6.0 ? c, the charge at the lower left corner is ? 2.4 ? c, and the charge at the lower right corner is ? 9.0 ? c. a. what is the net electric force on the + 3.0 ? c charge? b. what is the net electric force on the ? 6.0 ? c charge? c. what is the net electric force on the ? 9.0 ? c charge?

Afigure skater is rotating at a rate of 200 revolutions per minute. what is the angular speed, in units of rad/s? 20.9 12000 200 3.33

Which branches of natural science include the study of an organism that lived 10 million years ago

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)