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free/or 0.5$ |
| 55663 | In Problem 71, let the height h equal 6.00 m and the speed vboy equal 2.00 m/s. Assume that the food pack starts from rest.
(a) Tabulate and graph the speed–time graph.
(b) Tabulate and graph the acceleration-time graph. Let the range of time be from 0 s to 5.00 s and the time intervals be 0.500 s. |
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| 55664 | In practical heat engines, which are we better able to control: the temperature of the hot reservoir or the temperature of the cold reservoir? Explain. |
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| 55665 | In a period of 1.00 s, 5.00 X 1023 nitrogen molecules strike a wall with an area of 8.00 cm2. If the molecules move with a speed of 300 m/s and strike the wall head-on in elastic collisions, what is the pressure exerted on the wall? (The mass of one N2 molecule is 4.68 X 10-26 kg.) |
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| 55666 | In our model of the kinetic theory of gases, molecules were viewed as hard spheres colliding elastically with the walls of the container. Is this model realistic? |
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| 55667 | In Mostar, Bosnia, the ultimate test of a young man’s courage once was to jump off a 400-year-old bridge (now destroyed) into the River Neretva, 23.0 m below the bridge.
(a) How long did the jump last?
(b) How fast was the diver traveling upon impact with the water?
(c) If the speed of sound in air is 340 m/s, how long after the diver took off did a spectator on the bridge hear the splash? |
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| 55668 | In making raspberry jelly, 900 g of raspberry juice is combined with 930 g of sugar. The mixture starts at room temperature, 23.0°C, and is slowly heated on a stove until it reaches 220°F. It is then poured into heated jars and allowed to cool. Assume that the juice has the same specific heat as water. The specific heat of sucrose is 0.299 cal/g °C
Consider the heating process. (a) Which of the following terms describe(s) this process: adiabatic, isobaric, isothermal, isovolumetric, cyclic, reversible, isentropic?
(b) How much energy does the mixture absorb?
(c) What is the minimum change in entropy of the jelly while it is heated? |
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| 55669 | In an insulated vessel, 250 g of ice at 0°C is added to 600 g of water at 18.0°C.
(a) What is the final temperature of the system?
(b) How much ice remains when the system reaches equilibrium? |
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| 55670 | In Figure P20.40, the change in internal energy of a gas that is taken from A to C is "800 + J. The work done on the gas along path ABC is - 500 J.
(a) How much energy must be added to the system by heat as it goes from A through B to C?
(b) If the pressure at point A is five times that of point C, what is the work done on the system in going from C to D?
(c) What is the energy exchanged with the surroundings by heat as the cycle goes from C to A along the green path?
(d) If the change in internal energy in going from point D to point A is "500 J, how much energy must be added to the system by heat as it goes from point C to point D? |
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| 55671 | In Figure 2.10b, the area under the velocity versus time curve and between the vertical axis and time t (vertical dashed line) represents the displacement. As shown, this area consists of a rectangle and a triangle. Compute their areas and compare the sum of the two areas with the expression on the right-hand side of Equation 2.12. |
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| 55672 | In an experimental house, Styrofoam beads were pumped into the air space between the panes of glass in double windows at night in the winter, and pumped out to holding bins during the day. How would this assist in conserving energy in the house? |
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| 55673 | In describing his upcoming trip to the Moon, and as portrayed in the movie Apollo 13 (Universal, 1995), astronaut Jim Lovell said, “I’ll be walking in a place where there’s a 400-degree difference between sunlight and shadow.” What is it that is hot in sunlight and cold in shadow? Suppose an astronaut standing on the Moon holds a thermometer in his gloved hand. Is it reading the temperature of the vacuum at the Moon’s surface? Does it read any temperature? If so, what object or substance has that temperature? |
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| 55674 | In deep space the number density of particles can be one particle per cubic meter. Using the average temperature of 3.00 K and assuming the particle is H2 with a diameter of 0.200 nm,
(a) Determine the mean free path of the particle and the average time between collisions.
(b) What If? Repeat part (a) assuming a density of one particle per cubic centimeter. |
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| 55675 | In a daring lecture demonstration, an instructor dips his wetted fingers into molten lead (327°C) and withdraws them quickly, without getting burned. How is this possible? (This is a dangerous experiment, which you should NOT attempt.) |
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| 55676 | In a cylinder of an automobile engine, just after combustion, the gas is confined to a volume of 50.0 cm3 and has an initial pressure of 3.00 X 106 Pa. The piston moves outward to a final volume of 300 cm3, and the gas expands without energy loss by heat.
(a) If y = 1.40 for the gas, what is the final pressure?
(b) How much work is done by the gas in expanding? |
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| 55677 | In a crude model (Fig. P21.35) of a rotating diatomic molecule of chlorine (Cl2), the two Cl atoms are 2.00 X 10 -10 m apart and rotate about their center of mass with angular speed = 2.00 X 1012 rad/s. What is the rotational kinetic energy of one molecule of Cl2, which has a molar mass of 70.0 g/mol? |
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| 55678 | In a constant-volume process, 209 J of energy is transferred by heat to 1.00 mol of an ideal monatomic gas initially at 300 K. Find
(a) The increase in internal energy of the gas,
(b) The work done on it, and
(c) Its final temperature. |
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| 55679 | In a constant-volume gas thermometer, the pressure at 20.0°C is 0.980 atm. (a) What is the pressure at 45.0°C? (b) What is the temperature if the pressure is 0.500 atm? |
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| 55680 | In Colonization: Second Contact (Harry Turtledove, Ballantine Publishing Group, 1999), the Earth has been partially settled by aliens from another planet, whom humans call Lizards. Laboratory study by humans of Lizard science requires “shifting back and forth between the metric system and the one the Lizards used, which was also based on powers of ten but used different basic quantities for everything but temperature.” Why might temperature be an exception? |
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| 55681 | In a chemical processing plant, a reaction chamber of fixed volume V0 is connected to a reservoir chamber of fixed volume 4V0 by a passage containing a thermally insulating porous plug. The plug permits the chambers to be at different temperatures. The plug allows gas to pass from either chamber to the other, ensuring that the pressure is the same in both. At one point in the processing, both chambers contain gas at a pressure of 1.00 atm and a temperature of 27.0°C. Intake and exhaust valves to the pair of chambers are closed. The reservoir is maintained at 27.0°C while the reaction chamber is heated to 400°C. What is the pressure in both chambers after this is done? |
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| 55682 | In a 30.0-s interval, 500 hailstones strike a glass window of area 0.600 m2 at an angle of 45.0° to the window surface. Each hailstone has a mass of 5.00 g and moves with a speed of 8.00 m/s. Assuming the collisions are elastic, find the average force and pressure on the window. |
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