Physics H131: Hints for Problem Set #8

Chapter C12 Problems

• C12T.1: I know that you know the answers. Give a good explanation!
• C12T.6: What is the criterion again for an elastic collision?
• C12T.8: Use your knowledge of conservation laws!
• C12B.6: This is very similar to Example C12.3 (p. 216)
• C12S.5: What is the power associated with the water dropping? Under the given conditions, how much of this power could you convert to electric power?
• C12S.12: Before you start working on this problem, you should read again Section C12.6. Use the mass, dimensions and kinetic energy given there for the asteroid. (a) How much energy is required to vaporize 1 kg of water with initial deep ocean temperature of 4 degree Celsius? What kind of energy? (b) What kind of energy change are we talking about here? (c) Don't forget to add both the splashed water and the vaporized water. When you look at your result, what do you think will happen with all this water? (d) How much water of initial temperature of 4 degree Celsius can you boil with 10 percent of the asteroid's energy? How would that affect our weather?
• C12R.1: This problem is rather similar to the inelastic collision problem discussed in Example C12.5 on p.223. Analyze both scenarios in turn. How much can you get out of momentum conservation? What does the energy balance tell you? Simplify the calculation by inserting the values for cos(theta), sin(theta) algebraically (not numerically - e.g. use sqrt(2), not 1.41...), but do the rest of the calculation symbolically!

Chapter C13 Problems

• C13T.4-6: These are simple cross product problems. Use your knowledge of cross products.
• C13S.1: How does one calculate the area of a parallelogram? Draw one and compare with Figure C13.2.