Calculate the power required for heating a 1.5 kg sample of water for 10 minutes in a thermal system. What is the amount of energy required to raise the temperature of the water from 25°C to 60°C ? How much minimum amount of power does the heater have to supply per unit time? Why does the actual power rating of the heater need to be higher than this minimum amount? (The specific heat of water is 4.18 J/g°C .) *60 points to anyone who can help*

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2