Concept explainers
You are watching a new bridge being built near your house. You notice during the construction that two concrete spans are placed end to end to form a span of length Li. However, they are placed end to end so that no room is allowed for expansion (Fig. P18.11a). In the opening storyline for this chapter, we talked about buckling sidewalks. The same thing will happen with spans on bridges if allowance is not made for expansion (Fig. P18.11b). You want to warn the construction crew about this dangerous situation, so you calculate the height y to which the spans will rise when they buckle in response to a temperature increase of ΔT.
Trending nowThis is a popular solution!
Chapter 19 Solutions
Physics for Scientists and Engineers, Technology Update (No access codes included)
- A vertical cylinder of cross-sectional area A is fitted with a tight-fitting, frictionless piston of mass m (Fig. P18.40). The piston is not restricted in its motion in any way and is supported by the gas at pressure P below it. Atmospheric pressure is P0. We wish to find the height h in Figure P18.40. (a) What analysis model is appropriate to describe the piston? (b) Write an appropriate force equation for the piston from this analysis model in terms of P, P0, m, A, and g. (c) Suppose n moles of an ideal gas are in the cylinder at a temperature of T. Substitute for P in your answer to part (b) to find the height h of the piston above the bottom of the cylinder. Figure P18.40arrow_forwardA vertical cylinder of cross-sectional area A is fitted with a tight-fitting, frictionless piston of mass m (Fig. P16.56). The piston is not restricted in its motion in any way and is supported by the gas at pressure P below it. Atmospheric pressure is P0. We wish to find die height h in Figure P16.56. (a) What analysis model is appropriate to describe the piston? (b) Write an appropriate force equation for the piston from this analysis model in terms of P, P0, m, A, and g. (c) Suppose n moles of an ideal gas are in the cylinder at a temperature of T. Substitute for P in your answer to part (b) to find the height h of the piston above the bottom of the cylinder.arrow_forwardA cylinder that has a 40.0-cm radius and is 50.0 cm deep is filled with air at 20.0C and 1.00 atm (Fig. P10.74a). A 20.0-kg piston is now lowered into the cylinder, compressing the air trapped inside as it takes equilibrium height hi (Fig. P16.74b). Finally, a 25.0-kg dog stands on the piston, further compressing the air, which remains at 20C (Fig. P16.74c). (a) How far down (h) does the piston move when the dog steps onto it? (b) To what temperature should the gas be warmed to raise the piston and dog back to hi?arrow_forward
- A 40.0-g projectile is launched by the expansion of hot gas in an arrangement shown in Figure P12.4a. The cross sectional area of the launch tube is 1.0 cm2, and the length that the projectile travels down the tube after starting from rest is 52 cm. As the gas expands, the pressure varies as shown in Figure P12.4b. The values for the initial pressure and volume are P1 = 11 105 Pa and Vi = 8.0 cm3 while the final values are Pf = 1.0 105 Pa and Vf = 8.0 cm3. Friction between the projectile and the launch tube is negligible, (a) If the projectile is launched into a vacuum, what is the speed of the projectile as it leaves the launch tube? (b) If instead the projectile is launched into air at a pressure of 1.0 105 Pa. what fraction of the work done by the expanding gas in the tube is spent by the projectile pushing air out of the way as it proceeds down tile tube?arrow_forwardDuring inhalation, a person's diaphragm and intercostal muscles contract, expanding the chest cavity and lowering the internal air pressure below ambient so that air flows in through the mouth and nose to the lungs. Suppose a person's lungs hold 1240 mL of air at a pressure of 1.00 atm. If they expand their chest cavity by 515 mL while keeping their nose and mouth closed so that no air is inhaled, what will be the air pressure in their lungs in atm? Assume the air temperature remains constant.arrow_forwardA plastic bar ACB having two different solid circular sections is held between rigid supports as shown in the figure. The diameters in the left- and right-hand parts are 50 mm and 75 mm, respectively. The corresponding lengths are 230 mm and 320 mm. The modulus of elasticity E is 6 GPa & the coefficient of thermal expansion α is 10-4 /0C. The bar is subjected to uniform temperature increase of 300C. Determine: i. maximum compressive stress in the bar. ii. displacement of point C.arrow_forward
- A pressure versus volume (pv) diagram for a system is shown in the figure. The arrows of the curve indicate the direction of the process, and the points of interest are labeled. The values for the points in the diagram are shown in the table. Volume (m3) Pressure (Pa) v0=27.4 p0=1.00×104 v1=19.3 p1=1.00×104 v2=16.0 p2=4.92×103 v3=13.3 p3=4.92×103 v4=13.3 p4=3.20×103 v5=7.51 p5=1.00×103 Calculate the amount of work done on the system from 0–2 (W02) and then for the entire curve from 0–5 (W05).arrow_forwardA flanged bolt coupling consists of ten steel 1/2-in.-diameter bolts spaced evenly around a bolt circle 14 in. in diameter. Determine the torque capacity of the coupling if the allowable shearing in the bolts is 6000 psi.arrow_forwardAn expandable cylinder has its top connected to a spring with force constant 2.00 x 103 N/m (Fig. P10.64). The cylinder is filled with 5.00 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 250°C? (b) What is the pressure of the gas at 250°C?arrow_forward
- The internal air pressure of a fridge reduces after closing its door due to cooling of air. If the temperature of all the trapped air falls from 30 deg Celcius to 5.0 deg Celcius after closing the fridge door, what is the magnitude of the resulting net force on the door? Take the volume of trapped air to be 0.30 m3, take the fridge to be perfectly sealed, and take the door area that is in contact with the trapped air to be 0.60 m2?arrow_forwardA 40.0g projectile is launched by the expansion of hot gases as shown. The cross sectional area of the launch tube is 1.0cm^2 and the length the projectile travels down the tube is 32cm. As the gas expands, the pressure and volume varies as shown. The initial pressure and volume are 11e5 Pa, and 8.0cm^3, and the final pressure and volume is 1.0e5Pa and 40.0cm^3. Friction with the launch tube is negligible. a) If the projectile is fired into vacuum, what is the speed of the projectile when it leaves the tube? b) If the projectile is launched into a room where the air pressure is 1.0e5Pa, how much energy is spent pushing the air out of the way as the projectile moves down the barrel? (Hint: What is the work exerted on the projectile by the air in the room? Also, think about which thermodynamic variable(s), describing the air in the room, you can approximate as constant.) Answer both partsarrow_forwardA liquid with a coefficient of volume expansion of β just fills a spherical flask of volume V 0 at temperature Ti (Fig. P10.57). The flask is made of a material that has a coefficient of linear expansion of a. The liquid is free to expand into a capillary of cross- sectional area A at the top. (a) Show that if the temperature increases by ΔT, the liquid rises in the capillary by the amount Δh = (V0 /A)(β − 3α)ΔT. (b) For a typical system, such as a mercury thermometer, why is it a good approximation to neglect the expansion of the flask?arrow_forward
- Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning