Question

tank contains 335 kg of water at a uniform temperature of 60oC. The tank is insulated and not heated; it neither loses nor gains heat through the walls of the tank. A valve is opened and water exits the tank at a rate of 0.5 kg/sec and a temperature of 60oC. After 10 seconds the valve is closed again . Using the assumption that water at zero degrees centigrade contains zero energy and considering only internal, how much energy left the tank through the valve during this 10 second period; report as kJ.

Answer 1

Step-by-step explanation:

Thermal energy or internal energy gain or loss = mass x specific heat x temperature

specific heat of water = 4.2 kJ / kg degree Celsius

mass of water lost in 10 second = rate of loss x time = .5 x 10 = 5 kg .

heat energy associated with lost water = 5 x 4.2 x ( 60 - 0 ) = 1260 kJ .

Heat energy lost = 1260 kJ .