during a process, 21.6 MJ of heat is added to closed system. if the internal energy is increased by 59.6 MJ, how much work in Btu was done? is the work done on ro by the system?
To calculate the work done in Btu, we need to convert the given values from the metric system (MJ) to the British thermal units (Btu).
Let's first convert the given heat added (21.6 MJ) and the change in internal energy (59.6 MJ) to Btu.
1 Btu is equal to approximately 0.94782 kJ (kilojoules).
Converting the heat added:
21.6 MJ * 1000 kJ/MJ * 0.94782 Btu/kJ = 20,623.27 Btu (rounded to two decimal places)
Converting the change in internal energy:
59.6 MJ * 1000 kJ/MJ * 0.94782 Btu/kJ = 56,901.61 Btu (rounded to two decimal places)
So, the work done in Btu is approximately 56,901.61 Btu.
Now, let's determine whether the work done is by or on the system. In thermodynamics, the sign conventions for work are as follows:
- Positive work is done BY the system, meaning work is done ON the surroundings.
- Negative work is done ON the system, meaning work is done BY the surroundings.
In this case, since the work done is positive (56,901.61 Btu), it means that the work is done BY the system, which implies work is done ON the surroundings.
Therefore, the work done is 56,901.61 Btu, and it is done ON the system.