Question

It takes a resistance heater having 2 kW power to heat a room having 5 m X 5 m X 6 m size to heat from 0 to 32 oC at sea level. Calculate the amount of time needed for this heating to occur in min

Answer 1

Answer:

The amount of time needed for this heating to occur is 126.25 min

Explanation:

Given;

power required to heat the room = 2kW

volume of the room =  5 m X 5 m X 6 m = 150 m³

atmospheric pressure at sea level = 101 Kpa

Internal energy available in this room, E = PV

                                                               = 101 Kpa*150m³

                                                               = 15,150 Kpa.m³ = 15,150 KJ

P*t = E

where;

t is the time required to heat this room

1 kW = 3600 kJ/h

2 kW = 7200 kJ/h

$t = \frac{E}{P} = \frac{15150 KJ}{7200\frac{KJ}{h}} =2.104 {hours} = 126.25 min$

Therefore, the amount of time needed for this heating to occur is 126.25 min