Consider one mole of perfect gas in a cylinder of uniform cross section with a piston attached (Fig). A spring (spring constant k) is attached (unstretched lengthL) to the piston and to the bottom of the cylinder. Initially the spring is unstretched and the gas is in equilibrium. A certain amount of heat Q is supplied to the gas causing an increase of volume from V_(0)" to " V_(1). a) What is the initial pressure of the system b) What is the final pressure of the system c) Using the first law of thermodynamics, write down a relation between Q,P_(a),V,V_(0) and K .

Consider one mole of perfect gas in a cylinder of uniform cross sectio

1.	Consider one mole of perfect gas in a cylinder of uniform cross section with a piston attached (Fig). A spring (spring constant k) is attached (unstretched lengthL) to the piston and to the bottom of the cylinder. Initially the spring is unstretched and the gas is in equilibrium. A certain amount of heat Q is supplied to the gas causing an increase of volume from V_(0)" to " V_(1). a) What is the initial pressure of the system b) What is the final pressure of the system c) Using the first law of thermodynamics, write down a relation between Q,P_(a),V,V_(0) and K .
Answer» Solution :a) `P_(i)=P_(a)` b) `P_(F)=P_(a)+K/A[(V-V_(0))/A]=P_(a)+K/A^(2)(V-V)_(0)` C) `DeltaQ=P_(a)(V-V_(0))+1/2K[(V-V_(0))/A]^(2)+C_(V)(T-T_(0))` where `T_(0)=P_(a)V_(0)//R` `T=[PA+(K//A^(2)).(V-V_(0))]V//R`