Gas Thermodynamics 1

What is the equation for the first law of thermodynamics?

• U=Q+W
• U=Q-W
• U=-Q+W
• U+Q+W=0

The first law of thermodynamics is basically the same as which law from physics 1?

• Newton's first law
• The law of conservation of energy
• The law of conservation of momentum
• Newton's second law

When applying the first law of thermodynamics to a system, when is heat a positive quantity?

• when the system does work
• when the system has work done on it
• when the system absorbs heat
• when the system loses heat
• when no work is done either on the system or by the system

The product of the pressure and volume of a system  has the same SI units as which one of the following choices?

• force
• work
• acceleration
• momentum
• impulse

An open system is one in which

• Heat and work cross the boundary, but the mass does not

• Mass crosses the boundary, but the heat and work do not

• Heat, work and mass cross the boundary

• None of heat, work and mass cross the boundary

An ideal gas has a 100 kPa pressure and 300 K temperature. It is cooled at a constant pressure with a volume change of 300 cm³. How much is the work done by the gas?

• 30 J

• 3 kJ

• 2 J

• 400 J

An expandable container of Oxygen gas absorbs 14 J heat and expands from 60 cm³ to 120 cm³ under the constant pressure of 1kPa. Calculate the change in the internal energy of the gas.

• 8 J

• 5 J

• 4 J

• 3 J

A ideal gas with an internal energy of 3000 J absorbed 800 J of heat. Calculate the work done by the gas.

• -3800 J

• -2200 J

• 1000 J

• 3800 J