Problems14

Problems14
Download Document
Showing pages : 1 - 2 of 17
This preview has blurred sections. Sign up to view the full version! View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chapter 14 Problems 1, 2 , 3 = straightforward, intermediate, challenging Section 14.1 Pressure 1. Calculate the mass of a solid iron sphere that has a diameter of 3.00 cm. 2. Find the order of magnitude of the density of the nucleus of an atom. What does this result suggest concerning the structure of matter? Model a nucleus as protons and neutrons closely packed together. Each has mass 1.67 10 27 kg and radius on the order of 10 15 m. 3. A 50.0-kg woman balances on one heel of a pair of high-heeled shoes. If the heel is circular and has a radius of 0.500 cm, what pressure does she exert on the floor? 4. The four tires of an automobile are inflated to a gauge pressure of 200 kPa. Each tire has an area of 0.024 0 m 2 in contact with the ground. Determine the weight of the automobile. 5. What is the total mass of the Earth's atmosphere? (The radius of the Earth is 6.37 10 6 m, and atmospheric pressure at the surface is 1.013 10 5 N/m 2 .) Section 14.2 Variation of Pressure with Depth 6. (a) Calculate the absolute pressure at an ocean depth of 1 000 m. Assume the density of seawater is 1 024 kg/m 3 and that the air above exerts a pressure of 101.3 kPa. (b) At this depth, what force must the frame around a circular submarine porthole having a diameter of 30.0 cm exert to counterbalance the force exerted by the water? 7. The spring of the pressure gauge shown in Figure 14.2 has a force constant of 1 000 N/m, and the piston has a diameter of 2.00 cm. As the gauge is lowered into water, what change in depth causes the piston to move in by 0.500 cm? 8. The small piston of a hydraulic lift has a cross-sectional area of 3.00 cm 2 and its large piston has a cross-sectional area of 200 cm 2 (Figure 14.4). What force must be applied to the small piston for the lift to raise a load of 15.0 kN? (In service stations, this force is usually exerted by compressed air.) 9. What must be the contact area between a suction cup (completely exhausted) and a ceiling if the cup is to support the weight of an 80.0-kg student? 10. (a) A very powerful vacuum cleaner has a hose 2.86 cm in diameter. With no nozzle on the hose, what is the weight of the heaviest brick that the cleaner can lift? (Fig. P14.10a) (b) What If? A very powerful octopus uses one sucker of diameter 2.86 cm on each of the two shells of a clam in an attempt to pull the shells apart (Fig. P 14.10b). Find the greatest force the octopus can exert in salt water 32.3 m deep. Caution...
View Full Document