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INTRODUCTION AND BASIC CONCEPTS
Thermodynamics
1-1C Classical thermodynamics is based on experimental observations whereas statisticalthermodynamics
is based on the average behavior of large groups of particles.
1-2C On a downhill road the potential energy of the bicyclist is beingconverted to kinetic energy, and
thus the bicyclist picks up speed. There is no creation of energy, and thus no violation of the conservation
ofenergy principle.
1-3C There is no truth to his claim. It violates the second law of thermodynamics.
1-4C A car going uphill without the enginerunning would increase the energy of the car, and thus it would
be a violation of the first law of thermodynamics. Therefore, this cannot happen. Usinga level meter (a
device with an air bubble between two marks of a horizontal water tube) it can shown that the road that
looks uphill to the eyeis actually downhill.
Mass, Force, and Units
1-5C Pound-mass lbm is the mass unit in English system whereas pound-force lbf is the force unit.One
pound-force is the force required to accelerate a mass of 32.174 lbm by 1 ft/s2. In other words, the weight
of a 1-lbm mass at sea level is 1lbf.
1-6C In this unit, the word light refers to the speed of light. The light-year unit is then the product of a
velocity and time. Hence, thisproduct forms a distance dimension and unit.
1-7C There is no acceleration, thus the net force is zero in both cases.
PROPRIETARY MATERIAL.