2-6
A steel bar initially at 1000oF is quenched by immersion in a bath of liquid water initially at 70oF. The
mass of the bar is 2.5 lbm and the volume of the water is 7 ft3. Heat is transferred from the bath to the
surroundings, which are at 70oF. After

3-1
An arctic explorer builds a temporary shelter from wind-pack snow. The shelter is roughly
hemispherical with an inside radius of 1.5 meters. After completing the shelter, the explorer crawls
inside and closes off the entrance with a block of snow. Ass

3-18
The windshield of an automobile is heated on the inside by a flow of warm air. Cold air at 15F
flows over the exterior of the windshield. The heat transfer coefficient on the inside is 16
Btu/hft2F and the heat transfer coefficient on the outside is

2-37
A piston-cylinder assembly contains 0.4 kg of CO2. The gas expands at constant temperature from an
initial state of 250 kPa, 100C to a final pressure of 100 kPa. Calculate the heat transferred during the
process.
Approach:
Apply the formula for work

2-1
A 2000-kg car accelerates from 20 to 60 km/h on an uphill road. The car travels 120 m and the slope of the
road from the horizontal is 25o. Determine the work done by the engine.
Approach:
Apply the first law choosing the car to be the system
under co

1-3
For the following four systems, define a control volume, state if the system is steady or unsteady, open or
closed, constant volume or changing volume, constant fluid density or changing fluid density. Also,
identify all heat transfer, energy flows, a