In a solar water heater, energy from the Sun is gathered by

water that circulates through tubes in a rooftop collector.The solar

radiation enters the collector through a transparent cover and

warms the water in the tubes; this water is pumped into a holding

tank. Assume that the efficiency of the overall system is 20% (that

is, 80% of the incident solar energy is lost from the system).What

collector area is necessary to raise the temperature of 200 L of water

in the tank from 20°C to 40°C in 1.0 h when the intensity of

incident sunlight is 700 W/m2?