Energy Forms and Changes

Energy Forms and Changes 1) Open the Energy Forms and Changes Interactive Simulation found in the Syllabus and Study Guide under the Unit IV Lab Assignment. 2) Start this exercise by clicking on "Intro." (We will not be exploring the "Systems" part of this simulation.) 3) Click the "Energy Symbols" box in the upper right hand corner. (Clicking the "link heaters" is optional.) 4) Play with the simulator. Get comfortable with moving the beakers of water and oil to the stands. Move the thermometers into the liquids or onto the solids. Practice heating and cooling. 5) When you are ready to begin the assignment, move both beakers on top of the heating mantles, and place the thermometers, which are located in the upper left corner of the screen, into the liquids. The arrow to the left of the thermometer will turn the same color as the liquid when submerged. 6) Drag the bar on the heating mantle and hold it at maximum heat until the red liquid in the thermometer is at the top of the thermometer. In the boxes below, insert a screenshot of the beakers when they are at the maximum temperature (red liquid in the thermometer is at the top of the thermometer). This is the "Hot water & oil." You can take screenshots by selecting the three vertical dots in the bottom right hand corner of the simulation screen and then selecting “Screenshot.” A screenshot will be downloaded to your browser which you can save to your computer. 7) Repeat this procedure but cool both beakers with the liquids by dragging the bar to cool and holding at maximum cool until the liquid in the thermometer is at the bottom of the thermometer. Insert a screenshot of the "cool water & oil." 8) Take the beakers of liquids off the heating mantles and replace with the iron and brick. Move the thermometers to the solid objects you are about to heat & cool. 9) Drag the bar on the heating mantle and hold it at maximum heat until the red liquid in the thermometer is at the top of the thermometer. In the boxes below, insert a screenshot of the blocks when they are at the maximum temperature (red liquid in the thermometer is at the top of the thermometer). This is the "Hot iron & brick blocks." 10) Repeat this procedure but cool both blocks by dragging the bar to cool and holding at maximum cool until the liquid in the thermometer is at the bottom of the thermometer. Insert a screenshot of the "cool iron & brick blocks." Part I: 1. Hot Water & Oil Hot Iron & Brick Blocks Cool Water & Oil Cool Iron & Brick Blocks 2. At the molecular level, what form of energy do the molecules have? During the process of applying heat to both the brick and iron, the molecules, at the molecular level, thermal energy. 3. Heat up the brick and the iron to the same temperature. What differences do you notice? Prior to applying heat to the material, the iron shows to hold more energy molecules than the brick. As heat is applied to blocks, temperature increases at different rates; brick heats up faster than iron. As the iron and brick increase in temperature, the brick releases energy at a faster rate than the iron until the brick and iron reach the maximum temperature. At that time, the energy releases at the same rate into the surrounding air. When the heat is removed, the brick cools down at a faster rate than iron, releasing the energy much faster. Iron shows to retain the thermal energy for a longer period of time. Brick Iron 4. What does temperature measure? Support your answer with evidence from the simulation. “Temperature, a measure of the hotness or coldness of an object, is a physical property that determined the direction of heat flow” (Brown, LeMay, et al., 2018, p. 20). In this experiment, the temperature is measuring the amount of thermal energy that is being retained by the material. As the heat is applied, the internal temperature of the material rises to a higher temperature and when heat is removed, the temperature decreases. As shown in the simulation, the temperature of the iron starts to decrease first when the heat source is removed; however, the brick starts to decrease at a faster rate after a few seconds and soon after, the brick’s temperature measures lower than the iron, as the iron is retaining the thermal energy longer. 5. Put a hot object into cold water. Take a screenshot and then explain what happens to the energy in each of the stages. The diagram below is to give you a visual of what you should do. You should insert your screenshot & explanation below this diagram. Figure 1 below shows a beaker of water that has been cooler and a block of iron that has been heated. Figure 2 shows the heated iron inserted into the cooled water. Just after inserting the heated iron into the cooled water, energy is released at a rapid rate from the iron and the water absorbs the energy raising its temperature. In other words, energy is transferred from the iron to the water. Energy in the form of water vapor/steam is also released into the surrounding air. Figure 3 shows the energy in the water and iron returning to the state it was prior to cooling and heating, respectively (room temperature). Figure 1 Figure 2 Figure 3 6. When and why does the process in 5 stop? Figure 3 above shows the energy in the water and iron returning to the state it was prior to cooling and heating, respectively. The exothermic and endothermic process stops when the transfer of energy to and from the water and iron (system) equalizes.