An 8 TR cold-store plant works on the simple vapour-compression cycle with R134a shown on the p–h diagram in the figure; the specific enthalpies of the states are marked on the h-axis (1 TR = 3.5 kW). Determine (a) the mass flow rate of refrigerant (answer in kg/s), (b) the compressor power (answer in kW) and (c) the COP of the plant.