Insulation=> simple problem just confused a bit.

[~christina~]

Homework Statement

A house has well insulated walls. It contains a vol of 100m^3 of air at 300K

a) calculate the E required to increase the T of the diatomic gas by 1.00C

b) If this E could be used to lift an object of mass m through a height of 2.00m what is the mass of m?

Homework Equations

$$Q=m C_v \Delta T$$= > constant V
$$\Delta U= Q$$
$$C_v= 5R/2$$

$$Q=mC_p \Delta T$$=> constant P
$$\Delta U= Q + W= nC_p \Delta T + (-P\Delta V)$$
$$C_p= 7R/2$$

The Attempt at a Solution

a)calculate the E required to increase the T of the diatomic gas by 1.00C

I would think that the insulation would make the volume be constant but that's what I'm not sure about. (I was thinking that the temperature would be constant but if they ask how much E is needed to raise the temperature then it can't be that the temperature would be the same...)

b) b) If this E could be used to lift an object of mass m through a height of 2.00m what is the mass of m?
would I just use $$\Delta PE= mgh$$and find m ?

Help please..

Thank you very much.

 

[~christina~]

can someone help me please?

I have a quiz and if no one does then I'll be forced to assume that the volume doesn't change even if it may be incorrect.

 

[Moetasim]

I would first clarify the problem by asking for more information. Specifically, I would ask what type of insulation is being used in the walls of the house, as different types of insulation have different thermal properties and can affect the calculations. I would also ask for the specific heat capacity of the air in the house, as this will be needed to calculate the energy required to increase the temperature.

Once I have this information, I would use the equations provided to calculate the energy required to increase the temperature of the air by 1.00C. This would involve using the specific heat capacity at constant volume, as the volume is stated to be constant in the problem.

For part b, I would use the equation for change in potential energy to calculate the mass of the object that could be lifted using the energy calculated in part a. I would also take into consideration the efficiency of the insulation in retaining the heat, as this would affect the amount of energy available for lifting the object.