The pressure in a monoatomic gas increases linearly from 4 xx10^5Nm^(-2)to 8 xx 10^5Nm^(-2)when its volume increases from 0.2 m^3to 0.5 m^3. Calculate the following: increase in the internal energy,

The pressure in a monoatomic gas increases linearly from 4 xx10^5Nm^(-

1.	The pressure in a monoatomic gas increases linearly from 4 xx10^5Nm^(-2)to 8 xx 10^5Nm^(-2)when its volume increases from 0.2 m^3to 0.5 m^3. Calculate the following: increase in the internal energy,
Answer» Solution :GIVEN that, `P_1= 4 xx 10^5N//m^2, P_2 = 8 xx 10^5 N//m^2 , V_1 = 0.2 m^2, V_2= 0.5 m^3` For monoatomic gas :`C_v =(R )/(gamma -1) = (3R)/(2)= ( 3 xx8.3 )/(2)J// "MOLE `-K `therefore `Increase in internal energy, `Delta U=nC_v(T_2-T_1) =(C_v )/(R )(P_2 V_2-P_1V_1)` `=( 12.5 )/( 8.3) [8 xx 10^5 xx 0.5- 4 xx 10^5 xx 0.2 ] = 4.8 xx 10^5 J`