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### States of Matter Homework

1. Calculate the amount a copper rod (a=16 x 10-6/°C) 25 m long will expand when it is heated from 4°C to 124°C. Ans: 0.048 m
2. What is the volume difference for 2 liters of water (b=210 x 10-6/°C) at 5°°C and for water at 85°C? Ans: 0.034 L
3. An aluminum rod (a=25 x 10-6/°C) that is 250 m long is heated. What is its final temperature if the length of the rod increases 0.215 m? Its initial temperature is 20°C. Ans: 54.4°C
4. What is the change in length of a 15 m steel rail (a=12 x 10-6/°C) as it is cooled from 1535°C to 20°C? Ans: -0.27 m
5. A concrete sidewalk (b=36 x 10-6/°C) with dimensions of 8m x 1m x 0.1 m at exactly 0°C is heated to 35°C. What is its new volume? Ans: 0.801 m3
6. What is the mass of a lead sphere (r=11,300 kg/m3) with a volume of 0.523 m3? Ans: 5910 kg
7. What is the pressure due to a 30 m tall column of water? Ans: 2.9 x 105 N/m2
8. A 70 kg object is suspended in a lake. Its volume is 0.03 m3. What is the buoyant force exerted on the object by the water? Ans: 294 N
9. A 5 N force is applied to a piston 0f 0.5 m2 cross-sectional area of a hydraulic piston. What force must be applied to a 5 m2 cross-sectional area? Ans: 50 N
10. A solid cube of a certain material has a volume of 0.005 m3. It has a mass of 57.5 kg. What is its density? Ans: 11,500 kg/m3
11. What is the height of a column of water that exerts a pressure of 50,000 Pa? Ans: 5.10 m
12. A 20 N force is exerted on the small piston of a hydraulic system. The cross-sectional area of the small piston is 0.50 m2. What weight can be lifted by the large piston if it has a surface area of 1.00 m2? Ans: 40 N
13. A buoyant force of 20 N acts on an object suspended in alcohol (r=800 kg/m3). What is the volume of the object? Ans: 0.0026 m3
14. Water flows through the bottom of a tapered pipe at the rate of 6 m/s. The bottom of the tapered pipe has a cross-sectional area of 0.100 m2. What will be its rate of flow through the top of the tapered pipe where the cross-sectional area is 0.035 m2? Ans: 17.14 m/s
Thermal Energy Notes