First, we need to calculate the pressure exerted by the piston due to its weight and the atmospheric pressure.
The pressure exerted by the piston due to its weight is given by P_piston = m*g/A, where:
- m is the mass of the piston = 60 kg,
- g is the gravitational acceleration = 9.8 m/s^2, and
- A is the cross-sectional area of the piston = 0.04 m^2.
P_piston = 60 kg * 9.8 m/s^2 / 0.04 m^2 = 14700 Pa = 0.147 bar.
The total pressure inside the cylinder is the sum of the atmospheric pressure and the pressure due to the weight of the piston:
P_total = P_atmosphere + P_piston = 0.97 bar + 0.147 bar = 1.117 bar.
As for the second part of your question, when the volume of a gas is doubled due to the addition of heat (assuming this is an ideal gas), the change in pressure depends on the nature of the process.
If the process is isobaric (constant pressure), the pressure inside the cylinder will remain the same because the external pressure (atmospheric pressure plus the weight of the piston) remains constant.
If the process is isochoric (constant volume) or adiabatic (no heat exchange with the environment), the pressure would typically increase.
However, given that the volume changes (doubles in this case), this situation does not seem to follow an isochoric or adiabatic process. If we assume the process to be isothermal (constant temperature), the pressure would decrease since the volume has increased, based on Boyle's Law (P1*V1 = P2*V2). But this scenario is less likely because it is mentioned that heat is added to the system.