# Assign2-1 - Problem Statement 27 A personal computer is to...

This preview shows pages 1–2. Sign up to view the full content.

Problem Statement: 27 A personal computer is to be examined from a thermodynamic perspective. Determine the direction of the work and heat transfers (in or out) when the: a) keyboard c) processing unit b) monitor d) all of these are taken into account Schematic: c b d a Assumptions/Approximations: None needed Physical Laws: Properties/Sources: Conversions: Calculations: None needed None needed None needed Reasoning/Verification/Discussion: The work done on the keys when they are depressed is work done on the system (i.e., keyboard). The flow of electrical current (with its voltage drop) does work on the key Since the temperature of the electrical parts of the keyboard is somewhat higher than that of the surrounding air, there is a transfer of heat from the keyboard to the surround of the monitor are higher than that of the surrounding air. Hence there is a heat transfer to the surroundings. Energy in - Energy out = Energy ( a ) As one types on the keyboard, electrical signals are produced and transmitted to the processing unit. Simultaneously, the temperature of the electrical parts is increased ( b ) The monitor is powered by the electrical current supplied to it. This current (and voltage drop) is work done on the system (i.e., monitor).

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 5

Assign2-1 - Problem Statement 27 A personal computer is to...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online