Science practice 60

Two experiments were performed to study Newton’s laws of motion using air track gliders. The friction between the gliders and the air track is nearly zero. Each glider has a spring attached on each end.

Experiment 1

Two identical gliders were placed on an air track as shown in Figure 1. The gliders’ springs were then compressed completely together along with the gliders and released. When the gliders were pushed apart by their springs, the data in Table 1 was recorded. The zero position was recorded as the far-left point where Glider 1 is shown in Figure 1.

Table 1

Figure 1

Experiment 2

The same experiment was performed but Glider 3 was a double-weight glider in the first trial. In the second trial, Glider 4, a triple-weight glider, was tested.

Table 2

The velocity for each trial was calculated and the ratio of Glider 1 to the other glider was graphed and shown in Figure 2.

Figure 2

Since carbon is essential to life on Earth, understanding the global carbon cycle can provide valuable information. Through the process of photosynthesis, plants on land or algae living in water convert carbon dioxide into organic products. Through the process of respiration, organisms convert these organic compounds into energy and release carbon dioxide. Figure 1 displays the global carbon cycle.

Figure 1

A significant amount of carbon is released through the burning of fossil fuels. Some of this carbon is stored in the atmosphere, while a significant portion is stored in ocean waters and sediments. Carbon in the ocean is described as dissolved inorganic carbon, particulate inorganic carbon, particulate organic carbon (POC), and dissolved organic carbon (DOC). Particulates are defined as those larger than 0.2 micrometers, whereas dissolved matter is that smaller than 0.2 micrometers (see Figure 2).

Figure 2

Chromophoric dissolved organic matter (CDOM) is the colored portion of DOC. It is colored because it intensely absorbs violet and blue light. Figure 3 displays DOC and CDOM absorption in the tropical North Atlantic Ocean.

Figure 3