Q- A household refrigerator that has a power input of 450W and a COP of 2.5 is to cool 5 large watermelons, 10 kg each, to 10^oC. If the melons are initially at 20^oC, determine how long it will take for the refrigerator to cool them. The specific heat of melons = 4.2 kJ/(kg.^oC)

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