Problem: To reenact James Watt's experiment, John sealed some water in a container. He called this stage of his experiment as stage A. Then he started heating the water in the sealed container. He labeled this stage as stage B. Once the temperature reached hundred degree centigrade, he added more heat to it. He called this stage as stage C. Once all the water has turned into steam, he kept adding heat to it. He called this last stage of is experiment as stage D. Would stage C have higher or lower temperature than stage D? Hint: Continued heating of the water after the ice has completely melted will now increase the kinetic energy of the liquid molecules and the temperature will rise. Assuming that the atmospheric pressure is standard, the temperature will rise steadily until it reaches 100C. At this point, the added energy from the heat will cause the liquid to begin to vaporize. As with the previous state change, the temperature will remain at 100C while the water molecules are going from the liquid to the gas or vapor state. Once all the liquid has completely boiled away, continued heating of the steam (remember the container is closed) will increase its temperature above 100C.

A: lower

Problem: Two engineering students learned about petroleum products, While Dan learned more about plastics, Jim learned about fuels. Which student learned more about fuels for airplanes? Hint: A major use for petroleum products is fuel for cars, trucks, airplanes, trains, and other vehicles. The chemical used are usually a mixture of compounds containing several carbon atoms in a chain. When the material is ignited, a massive amount of gas is created almost instantaneously. This increase in volume will move the pistons in an internal combustion engine to provide power. A jet plane works on a similar principle. Air comes into the front of the engine and mixes with the jet fuel. This mixture is ignited and the gases formed create a lot of pressure to push the plane forward. The idea can be seen even more clearly in the case of a rocket launch. The ignition of the fuel (either solid-state or liquid) creates gases produced under great pressure that pushes the rocket up.

A: Jim

Problem: Mark has just graduated high school and is going to visit his grandpa, Tom, over the summer for a couple days. Since Tom is retired, he often has plenty of time to go fishing, and he even has a small cabin by the lake. The two men are planning to spend several days at the cabin cooking, fishing, chopping firewood to make fires and just general outdoor activities. Who will more quickly start to reel in a fish? Hint: Old age begins in the mid-60s and lasts until the end of life. Many people over 65 have retired from work, freeing up their time for hobbies, grandchildren, and other interests. Stamina, strength, reflex time, and the senses all decline during old age, and the number of brain cells decreases as well. The immune system becomes less efficient, increasing the risk of serious illnesses such as cancer and pneumonia. Diseases such as Alzheimer's disease that cause loss of mental function also become more common.

A: Tom

Problem: Marie is walking through the garbage dump when she spots two old drums that are used to store waste materials. Curious about what these drums contain, Marie reads the stickers on the side of each one. Drum P says "nuclear waste" on the side, and drum X says "sulfuric acid" on the side. Which drum will cause a weaker reaction in a Geiger counter? Hint: You generally can't see, smell, taste, hear, or feel radiation. Fortunately, there are devices such as Geiger counters that can detect radiation. A Geiger counter, like the one pictured in the Figure below , contains atoms of a gas that is ionized if it encounters radiation. When this happens, the gas atoms change to ions that can carry an electric current. The current causes the Geiger counter to click. The faster the clicks occur, the higher the level of radiation.

A:
drum X