Physics HW

Overview

1. A man has trapped himself in an isolated room. The room can be assumed as a system. The man walks inside the room for 5 hours and does 1250 J of work. In the process, his internal energy decreased by 2250 J. Determine the amount of heat (Q) including the algebraic sign exchanged between the system and the surrounding environment. What will happen to the internal energy of the man if the system gains about 3000 J of heat from the environment while performing the same amount of work?
2. A system, while at a constant pressure of 2.5×105 Pascal, gains heat such that the work done by the system is 4500 J. How much change will happen to the total volume of the system?
3. An isothermal process is where the temperature of the system remains constant throughout the process. So in one such process, a system containing four moles of an ideal gas is compressed to one-fifth of its initial volume found at 375 K. How much heat is removed from the system during this compression process?
4. A car engine has an efficiency of 30.0% and produces 4000 J of work. How much heat is rejected by the engine?
5. An ideal, or Carnot heat pump is used to heat a house in Denton on an extremely cold winter day. The inside temperature of the house is maintained at 300 K. How much work must the pump need to do to deliver 5000 J of heat into the house when the outside temperature is 265 K?