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sodium.dioxid
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In a cylinder (with a piston) containing gas, why do we use the external pressure, instead of the pressure of the gas, to calculate work?
Woopydalan said:I think it would be because all the internal forces cancel each other out.
sodium.dioxid said:In a cylinder (with a piston) containing gas, why do we use the external pressure, instead of the pressure of the gas, to calculate work?
Infinitum said:Internal pressure changes in all processes except isobaric. External pressure does not. Also, the work done on the system by the surrounding is easier to understand in terms of external pressure.
Work done by gas is the measure of the energy transferred when a gas expands or contracts under certain conditions. It is a physical quantity that represents the force applied by the gas multiplied by the distance it moves.
To calculate work done by gas, you need to know the force applied by the gas and the distance it moves. The formula for calculating work done by gas is W = F x d, where W is work, F is force, and d is distance.
The SI unit for work is joules (J), so the units for work done by gas are also joules. However, in some cases, other units such as calories or kilowatt-hours may be used to measure work done by gas.
The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. So, work done by gas is directly related to the change in internal energy of the gas.
Yes, work done by gas can be negative if the gas is compressed and the direction of force is opposite to the direction of motion. In this case, the work done by the gas is considered to be negative as the gas is losing energy instead of gaining it.