Thermodynamics

1. The problem statement, all variables and given/known data

Consider water contained in a cylinder at 25C with a frictionless piston with some weights on it. Initially the pressure inside the piston is 100kPa and then the water is heated such that the water does 290kJ/kg of work on the piston. Find the final temperature of the water.





2. Relevant equations

First Law: E_in-E_out=ΔE_system





3. The attempt at a solution

Since heat is added and work in done by the system, by the first law,

q_in-w_out=Δe_system=Δu=c_v(T₂-T₁)



q-290=c_v(T₂-T₁)



But how can I get q in order to calculate T₂?



Thank you