A solar water heating plant is using a flat-plate solar collector with an area  A of 28 m2. The collector is operating as follows: • Cold water temperature at the collector inlet Tin = 33°C • Hot water temperature at the collector outlet Tout = 57°C • Effective optical efficiency of the collector ηopt = 0.8 • Effective overall heat loss coefficient of the collector Uc,e = 3.9 W/m2K • Ambient air temperature Ta = 27°C • Solar radiation flux incident on the tilted collector surface Ic = 830 W/m2 • Isobaric specific heat of the water cp = 4187 J/(kg K)  Calculate (i) the useful heat output rate of the collector, and (ii) the water  mass flow rate in the collecto

The front window of an automobile has a thickness of 4 mm and is defrosted by the passage of a stream of hot air through the inner surface. The thermal conductivity of glass is around 0.78 W/(m oC). Assume the ambient air temperature is -10°C and the external convection coefficient is 65W/(m2 K). If the hot air blowing to defog the glass internally is at 40 ºC and the internal convection coefficient corresponds to 30 W/(m2 K), the internal surface temperatures will be _____________. However, if the car accelerates and maintains high speed, the external convection coefficient should _____________  [increase or decrease?] and if the condition is maintained long enough the temperature of the inner surface of the glass should _____________  [increase or decrease?].

IMPORTANT!!! ONLY ANSWER PART D Parts A, B, and C are solved and the answers are in the picture.

Based on the following information, how does a 1000W microwave compare to the stovetop and electric kettles in terms of water-heating efficiency? Calculate both electricity-to-heat and overall efficiency (assuming electricity from a natural gas fired power plant). Please express your answer as a percentage. ​ -A 1000W microwave takes 120 seconds to boil 8 oz of water. -The boiling point of water is 100°C, and room temperature water is 20°C -The specific heat of water is 4.186 J/gC