It's exam period and we are all very busy. Can't be expecting us to answer within mins right?
Anyway, I will give you some hints. First, 27C must be converted to 300K, because kelvins is the SI unit of temperature.
Since the mass of the piston is such that a pressure of 400kPa is required to move it, this means a few things (try drawing out on a P-V diagram)
Initially, heat is supplied at constant volume. Only pressure and temperature changes until the pressure reaches 400kPa. This is represented by a vertical upwards line on the P-V diagram. Using P/T as a constant, you will find that the final temperature is now 600K.
Then, because the piston will always move if the pressure of the gas exceeds 400kPa, the pressure of the gas is thus made to stay constant at 400kPa. This is represented by a horizontal rightwards line on the P-V diagram. Using V/T as a constant, since volume doubles, your final temperature T is 1200K.
So you have 3 points:
Point 1: P= 200kPa, V = V, n = n, T = 300K
Point 2: P= 400kPa, V = V, n = n, T = 600K
Point 3: P= 400kPa, V = 2V, n = n, T = 1200K
Work is only done between points 2 and 3.
n can be found by assuming air to be mostly nitrogen, so 3kg of air can be converted to number of moles. You can thus find work done = p (change in v) = nR (change in T)
As for heat supplied, you are only given Cv, which is heat capacity at constant volume. Heat capacity at constant pressure is not given. Hence, you may need to use the First Law of Thermodynamics between points 2 and 3 after finding the work done. Since air is mostly nitrogen and oxygen, we can assume it to be a diatomic gas, and has 5 degrees of freedom. The internal energy will thus be 5/2 nRT. With the change in temperature, you can find the change in internal energy.