Reference no: EM13995378
The first law of thermodynamics (which states that energy is conserved) does not specify the direction in which thermodynamic processes in nature can spontaneously occur. For example, imagine an object initially at rest suddenly taking off along a rough horizontal surface and speeding up (gaining kinetic energy) while cooling down (losing thermal energy). Although such a process would not violate conservation of energy, it is, of course, impossible and could never take place spontaneously.
The second law of thermodynamics dictates which processes in nature may occur spontaneously and which ones may not. The second law can be stated in many ways, one of which uses the concept of entropy.
a. An object at 20oC absorbs 25.0 J of heat. What is the change in entropy ΔS of the object? Express your answer numerically in joules per kelvin.
b. An object at 500 K dissipates 25.0 kJ of heat into the surroundings. What is the change in entropy ΔS of the object? Assume that the temperature of the object does not change appreciably in the process. Express your answer numerically in joules per kelvin.
c. An object at 400 K absorbs 25.0 kJ of heat from the surroundings. What is the change in entropy ΔS of the object? Assume that the temperature of the object does not change appreciably in the process. Express your answer numerically in joules per kelvin.
d. Two objects form a closed system. One object, which is at 400 K, absorbs 25.0 kJ of heat from the other object,which is at 500 K. What is the net change in entropy ΔSsys of the system? Assume that the temperatures of the objects do not change appreciably in the process. Express your answer numerically in joules per kelvin.
|
Explain and evaluate the relative worth of management jobs
: Explain and evaluate the relative worth of management jobs at the company and determine a compensation structure to assist retention and career management of this important element of the company's human resources.
|
|
Problem regarding the kolmogorov-smirnov test
: Apply either the chi-square or the Kolmogorov- Smirnov test for normality to the data described in Exercise 14.85. At the 0.05 level of significance, could the data have come from a normal population?
|
|
How many days per year must the firm operate to break even
: A seasonal bus tour firm has 5 buses with a capacity of 60 people each. Each customer pays $25 for a 1-day tour. The firm has an expense of $5/customer and a fixed annual cost of $360,000. If occupancy on the buses average 80% each day, how many days..
|
|
What is its profit-maximizing level advertising
: The elacity of demand for a firm’s product is - 2 and its advertising elasticity of demand is 0.1. determine the firm's optimal advertising -to-sales ratio? if the firm's revenues are $50,000, what is its profit-maximizing level advertising?
|
|
What is the change in entropy of the object
: Two objects form a closed system. One object, which is at 400 K, absorbs 25.0 kJ of heat from the other object,which is at 500 K. What is the net change in entropy ΔSsys of the system? Assume that the temperatures of the objects do not change appr..
|
|
Population median customer ratings
: Given the results in file XR14082, and using the 0.05 level of significance, examine whether the population median customer ratings for the three restaurants could be the same. Identify and interpret the p-value for the test.
|
|
The sum of private savings and public savings
: National savings is equal to the sum of private savings and public savings. To make our notation a bit easier, we will call national savings S, private savings V, and public savings U. So in other words, If private savings 'V' = 0.75S and total savin..
|
|
Firm sells its product in a perfectly competitive market
: A firm sells its product in a perfectly competitive market where other firms charge a price of $80 per unit. The firm's total costs are C(Q)=40+8Q+2Q2. how much output should the firm produce in the short run? what price should the firm charge in the..
|
|
What amounts from these investments are reported
: What amounts from these investments are reported in the comparative income statements? Has that income increased or decreased over the years reported?
|