26 March 2013

Physics Homework Ch10



1. For each of the following temperatures, find the equivalent temperature on the indicated scale.
a) -222.75°C on the Fahrenheit scale
_______°F

b) 98.4°F on the Celsius scale
_______°C

c) 115 K on the Fahrenheit scale
_______°F




2. The boiling point of liquid hydrogen is 20.3 K at atmospheric pressure.
a) What is the temperature on the Celsius scale?
_______°C

b) What is the temperature on the fahrenheit scale?
_______°F






3. The temperature difference between the inside and outside of a home on a cold day is 57.0°F.
a) Express this difference on the Celsius scale
_______°C

b) Express this difference on the Kelvin scale
__________ K





4. The New River Gorge bridge in West Virginia is a 518-m-long steel arch. How much will its length change between temperature extremes -16°C and 34°C?
____________ cm




5. A grandfather clock is controlled by a swinging brass pendulum that is 0.80 m long at a temperature of 21°C.
a) What is the length of the pendulum rod when the temperature drops to 0.0°C? (Round your answer to four significant figures.)
____________ mm

b) If a pendulum's period is given by T = 2π   L/g  , where L is its lenth, does the change in length of the rod cause the clock to run fast or slow?
  Fast   Slow  Neither (Select one)





6. The density of gasoline is 7.30 x 102 kg/m3 at 0°C. Its average coefficient of volume expansion is 9.60 x 10-4 (°C)-1, and note that 1.00 gal = 0.00380 m3.
a) Calculate the mass of 11.2 gal of gas at 0°C.
____________ kg

b) If 1.000 m3 of gasoline at 0°C is warmed by 16.5°C, calculate its new volume.
_________m3

c) Using the answer to part (b), calculate the density of gasoline at 16.5°C.
________ kg/m3

d) Calculate the mass of 11.2 gal of gas at 16.5°C.
_______kg

e) How many extra kilograms of gasoline would you get if you bought 11.2 gal of gasoline at 0° rather than at 16.5&degC from a pump that is not temperature compensated?
______ kg






7. The concrete sections of a certain superhighway are designed to have a length of 23.0 m. The sections are poured and cured at 10.0°C. What minimum spacing should the engineer leave between the sections to eliminate buckling if the concrete is to reach a temperature of 41.0°C? (Note: If applicable, Table 1 is available for use in solving this problem. See Textbook page 278)
_______ cm









8. One mole of oxygen gas is at a pressure of 5.60 atm and a temperature of 28.0°C.
a) If the gas is heated at constant volume until the pressure triples, what is the final temperature?
__________ °C

b) If the gas is heated so that both the pressure and volume are doubled, what is the final temperature?
__________ °C







9. An ideal gas occupies a volume of 1.2 cm3 at 20°C and atmospheric pressure.
a) Determine the number of molecules of gas in the container.
_________ molecules



b) if the pressure of the 1.2-cm3 volume is reduced to 2.0 x 10-11 Pa (an extremely good vacuum) while the temperature remains constant, how many moles of gas remain in the container?
__________ mol







10. Gas is confined in a tank at a pressure of 11.2 atm and a temperature of 26.0°C. If two-thirds of the gas is withdrawn and the temperature is raised to 74.0°C, what is the pressure of the gas reamining in the tank?
________atm






11. A weather balloon is designed to expand to a maximum radius of 24 m at its working altitude, where the air pressure is 0.030 atm and the temperature is 200 K. If the balloon is filled at atmospheric pressure and 253 K, what is its radius at liftoff?
________ m





6 comments:

  1. Delisa, You know you're not going to be watching any of the upcoming videos! Poser!!!

    ReplyDelete
  2. Awesome help! Thanks Mike

    ReplyDelete
  3. YW!
    So, anyone have a "Hardest" problem? I know I did. What was yours?

    ReplyDelete
  4. Can you solve this one. The question states "An expandable cylinder has its top connected to a spring with force constant 2.00 103 N/m (see figure below). The cylinder is filled with 4.00 L of gas with the spring relaxed at a pressure of 1.00 atm and a temperature of 20.0°C"

    (a) If the lid has a cross-sectional area of 0.0100 m2 and negligible mass, how high will the lid rise when the temperature is raised to Tf = 200°C?


    (b) What is the pressure of the gas at Tf = 200°C?

    The question is from chapter 10, question number 60 I believe.

    ReplyDelete
    Replies
    1. Start with the ideal gas law: PV=nRT
      Since their are two different states for the gas, set up two equations
      P1V1=n1RT1
      P2V2=n2RT2

      Divide the first equation by the second equation (n and R cancel out)
      P1V1/P2V2 = T1/T2

      Now, the pressure is equal to the force over the area (F/A)
      the force of the cylindar will be balanced perfectly by the force of the spring plus atmospheric pressure.
      Express the force of the spring: F/A = -Kx/A
      Express the change in volume in terms of area and its change in position
      deltaV = A*deltax, So then V2 is equal to V1 plus delta V.

      This would be much easier to explain on a video! LMK if this helps

      Delete