Q. Two cylindrical metal rods-one copper, the other lead-are connected in parallel with a temperature of 21.0 °C at one end and 112 °C at the other end. Both rods are 0.650 m in length, and the lead rod is 2.76 cm in diameter. If the combined rate of heat flow through the two rods is 33.2 J/s, what is the diameter of the copper rod?
Q. Two trains and a bird Two trains, each having a speed of 23 km/h, are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 70 km apart and heads directly for the other train. On reaching the other train it flies directly back to the first train, and so forth. (We have no idea why a bird would behave in this way.) What is the total distance the bird travels?