The surroundings include everything external to the system，and the system is separated from the surroundings by the system boundaries.
举一反三
- For a system, suppose it adsorb 100 kJ of heat from the surroundings and do 50 kJ of work to the surroundings, how much is its internal energy change? A: +150kJ B: -150 kJ C: 50 kJ D: -50 kJ
- A gas system absorbs 200J of heat and simultaneously does 300J work on surroundings at a given temperature, what is △U in joules for the gas system? A: +100 B: -200 C: +200 D: -100
- What does the autopilot system include?? Hydraulic system|Mechanical system|Electrical system|All of above
- The major components of automobile electrical system include starting system, charging system, ignition system and accessory system.
- In a feedback system, outputs from the system affect future activities of the system