Biology Forums - Study Force

A temperature difference of 5 K is equal to
 a. a difference of 9 on the Celsius scale.
  b. a difference of 9 on the Fahrenheit scale.
  c. a difference of 2.8 on the Rankine scale.
  d. a difference of .5 on the Fahrenheit scale.
  e. a difference of 2.8 on the Celsius scale.

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[Ques. 2] A pressure of 10.0 mm Hg is measured using a constant-volume gas thermometer at a temperature of 50.0C. What is the pressure (in mm Hg) at the zero-point temperature?
 a. 31.8
  b. 11.8
  c. 8.45
  d. 54.6
  e. 68.3

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[Ques. 3] A pressure of 10.0 mm Hg is measured at the triple-point of water using a constant-volume gas thermometer. What will the pressure be (in mm Hg) at 50.0C?
 a. 68.3
  b. 1.80
  c. 31.8
  d. 11.8
  e. 8.50

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[Ques. 4] In order for two objects to have the same temperature, they must
 a. be in thermal equilibrium.
  b. be in thermal contact with each other.
  c. have the same relative hotness or coldness when touched.
  d. have all of the properties listed above.
  e. have only properties (b) and (c) above.

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[Ques. 5] In order to understand the concept of temperature it is necessary to understand
 a. the zeroth law of thermodynamics.
  b. the first law of thermodynamics.
  c. the second law of thermodynamics.
  d. all of the above.
  e. only (b) and (c) above.

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[Ques. 6] Star A has a radius of 200 000 km and a surface temperature of 6 000 K. Star B has a radius of 400 000 km and a surface temperature of 3 000 K. The emissivity of both stars is the same. What is the ratio of the rate of energy radiated by Star A to that of Star B?

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[Ques. 7] In braking an automobile, the friction between the brake drums and brake shoes converts the car's kinetic energy into heat. If a 1 500-kg automobile traveling at 30 m/s brakes to a halt, how much does the temperature rise in each of the four 8.0-kg brake drums? (The specific heat of each iron brake drum is 448 J/kg/C).

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[Ques. 8] A styrofoam container used as a picnic cooler contains a block of ice at 0C. If 225 grams of ice melts in 1 hour, how much heat energy per second is passing through the walls of the container? (The heat of fusion of ice is 3.33  105 J/kg).

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[Ques. 9] How much water at 20C is needed to melt 1 kilogram of solid mercury at its melting point of 39C? (The heat of fusion of mercury is 2.8 cal/gram).

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[Ques. 10] 100 grams of liquid nitrogen at 77 K is stirred into a beaker containing 200 grams of 5C water. If the nitrogen leaves the solution as soon as it turns to gas, how much water freezes? (The heat of evaporation of nitrogen is 6.09 cal/gram and the heat of fusion of water is 80 cal/gram.)

1)  b

2)  c

3)  d

4)  a

5)  a

6)  4

7)  47C

8)  20.8 J (per second)

9)  23.4 grams

10)  none

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