Introduction:
On a hot, sunny day, would you rather wear dark or light-colored clothes? Have you ever walked across dark pavement barefoot on a hot day? How did that feel? Would you rather walk on the dark pavement or a lighter colored sidewalk along green grass? In this experiment you will investigate how the color of objects can affect it’s temperature.
Introduction:
Objective: The objective of today’s lab is to determine if water or sand heats up more quickly and “keeps” its heat longer. You will then use your collected data to answer the following question: How does a hot, sunny day at the beach affect a fish in the water differently from a crab on the sand? Explain.
Because of the fact that water expands when freezing, frozen water pipes can result in untold damage to a house. There are a variety of things that one can do to avoid this problem.
Here is a project that will challenge your students’ skill in interfacing PocketLab Voyager with Scratch Programming. The challenge is to program the five bubbles to start bubbling upwards in the teapot—one bubble at 90ᵒC, two at 92ᵒC, three at 94ᵒC, four at 96ᵒC, and five bubbles at 98ᵒC. When the temperature of the teapot has reached 100ᵒC, the phrase Full Boil should appear. See the movie accompanying this lesson for clarification of the intended result. When the burner under the real teapot is turned off and cooling begins, bubbling should go away in revers
PocketLab sensors can measure the pressure in a fluid line easily, by putting the PocketLab into a plastic wash bottle. (For protection, put the sensor in a ziplock bag with a paper towel.) The wash bottle nozzle inserts easily into 1/4" ID tubing, and can be used as a pressure tap to measure fluid pressure in two different T junctions.
PocketLab sensors work very well for measuring air and fluid pressure. To protect them, I have students seal them in a ziplock bag along with a paper towel (which absorbs any water that leaks in, keeping the sensor innards dry).
The attached lab worked very well to demonstrate the relationship between fluid column height and hydrostatic pressure. The hardest aspect is modifying the 5 gallon jug by mounting a nozzle connector to its side. It took dexterity, patience, and lots of silicon caulk.
A French watchmaker and physicist, Jean Charles A. Peltier, observed that electric currents produce heating or cooling at the interface between two dissimilar metals. This is now known as the Peltier effect and is used in numerous cooling applications, including air cooling of small refrigerators, beverage cooling in camping, cooling of electronic components, extraction of water in air by dehumidifiers, and cooling of CCDs in telescopes, spectrometers and cameras.
A common experiment for studying the reflectivity of different colored surfaces makes use of colored construction paper, aluminum foil, a light source, and a light sensor. Voyager’s light sensor and the little flashlight included with the Explorer Kit are perfect tools for performing this experiment. Empty graphs and data tables suitable for copying for student use are included with this lesson.
Students use warm soup (must be lower than 70°C since this is the upper limit of the pocketlab temperature sensor). To determine it's specific heat capacity and decide which is best to take on a camp so it is still warm when they go for lunch. I tend to use this as a follow on project from investigating insulating materials so students can re use previous projects such as 'stubby holder' style devices which have kept drinks cool to reinforce ideas about heat transfer (and so that projects aren't wasted!).
In this experiment students will use PocketLab to collect data related to the cooling of a container of hot water as time goes on. Sir Isaac Newton modeled this process under the assumption that the rate at which heat moves from one object to another is proportional to the difference in temperature between the two objects, i.e., the cooling rate = -k*TempDiff. In the case of this experiment, the two objects are water and air. Newton showed that TempDiff = To * exp(-kt), where TempDiff is the temperature difference at time t and To is the temperature difference at time zero.
