Chapter 24 Aggregate Demand Supply Model

Name: _________________________ Date: ___________ Period: ____ Online Simulation Lab  ROLLER COASTER PHYSICS Purpose: The purpose of this simulation lab is to strengthen your understanding of energy conservation in real-world applications. You will use a skateboarder and his park to represent the roller coaster and its track. You will observe many other physics concepts at work as well. Pre-Lab Inquiry What Do You Think? You are asked to design a new roller coaster. It is totally up to you to determine what the riders will experience. The only rule is that the coaster obeys the laws of physics. Take a minute and brainstorm about a design you would like. 1. Name three adjectives that will describe your roller coaster. Fantastic, graceful, crazy. 2. Describe three features your roller coaster will have that will attract riders. A large loop that leaves you hanging at the top for 30 seconds. A huge drop of 300ft. The roller coaster will also have water sprayed at the riders when they reach the end of the ride. 3. Name three variables that will affect the type of experience a rider will have. EXPLAIN. How crowdy the roller coaster is some may not want to get on if there are too many people. If the seat or belt is uncomfortable it’ll make the rider uncomfortable making them less likely to ride again. The speed of the roller coaster can affect the experience of the rider because if it is to slow it is not fun and if it is too fast it is dangerous. 4. Name three concepts of physics that the roller coaster must obey in order to be successful. EXPLAIN. Gravitation, potential and kinetic energy, and acceleration. Gravitation because gravity ensures movement along its track pushing riders forward and backwards in their seats. Potential and kinetic energy changes the roller coasters speed and height, it also helps maintain the rides balance. Acceleration because it changes the speed and direction, it helps the roller coaster accelerate through curves. 5. Draw a side-view sketch of your roller coaster design below. Concept Review Write out an explanation for each question below. 6. Define potential and kinetic energy. Potential energy refers to stored energy. Kinetic energy is energy in motion. 7. Describe when potential and kinetic energy are at their highest on a roller coaster. When the roller coaster is going down the hill it gains kinetic energy to push it through small turns. Potential energy is at its highest when the roller coaster is at the highest point. 8. How does conservation of energy apply to roller coasters? Energy can change form, but it cannot be created or destroyed. On a roller coaster energy changes from potential to kinetic energy and back again many times. 9. How does friction affect a roller coaster? On a roller coaster the wheels rub along the rails creating friction. 10. What is responsible for the apparent change in weight that riders experience on coasters? Acceleration, force, and gravity are responsible for change in wright. It pulls you rough the same direction making you feel much heavier than normal. Internet Lab Activity 1. 2. 3. 4. 5. 6. Go to Click “Play with Sims…>” Click the “Energy Skate Park” icon Click “Run Now!” Spend ONE MINUTE to explore the simulation and familiarize yourself with the controls. Click the “Reset” button in the top-right corner. Begin the exploration below. Exploration Questions Use the simulation to answer the questions below. 1. Does the skater hit the same height on the opposite sides of the track? (Checkmark the “Show Grid” button to help you determine this!) Yes, the skater hits the same height on the opposite side of the track. a. What must be true about the system for this to be possible? The energy is conserved. b. Click the “Track Friction >>” button to adjust the friction settings. What do you observe about the skater as you adjust the setting? What I see is that the skater starts slowing down after each time he goes back and forth on the track until eventually he stops. 2. Now, turn on the energy Pie Chart and Bar Graph. (You may need to move things around a little to see everything.) a. On the visual aids, what color represents potential energy and which is kinetic energy? Potential energy is blue and kinetic energy is green. b. When does the skater have the highest amount of kinetic energy? Potential energy? The skater has the highest kinetic energy when after starting at the top it reached the bottom curve. The skater has the highest potential energy when he is at the highest point on the track c. When does the skater have the lowest amount of kinetic energy? Potential energy? The skater has the lowest amount of kinetic energy when it stops or reaches a higher point. The skater reaches the lowest potential energy when the skater reaches the lowest point. d. Describe how the bar graph changes as the skater moves along the track. As the skater moves along the track the potential and kinetic energy start alternating, as one goes up the other goes down. The thermal energy also increases as the skater moves along the track. e. Explain which visual aid (pie chart or bar graph) helps you understand conservation of energy better, and why. The visual aid helps me understand conservation of energy because it shows me that potential and kinetic energy are changing but they never disappear, and new energy never appears. f. Keep your preferred visual aid open for the remainder of the investigation. My preferred visual aid is the bar graph. Build Your Roller Coaster Use the simulation to build and test your roller coaster design from the Pre-Lab Inquiry. 1. If you made any changes during the Exploration Questions, click “Reset” again. 2. Right-click the track and select “Roller Coaster Mode”. This keeps the skater attached. 3. Notice that you can zoom out to give yourself a wider view. You may want to do this as you build your coaster. 4. Drag in new pieces of track and manipulate the curves until you closely match your pre-lab sketch. 5. Drag and drop the rider to the location of the beginning and observe. DO NOT MAKE CHANGES YET. a. The ride probably was not successful on the first attempt. If not, what physics concept(s) was violated? The physics concept that was violated is that the roller coaster did not have enough acceleration to make it completely around the loop. b. Identify several adjustments you need to make. I would need to rearrange where to place the loop and the drop so the roller coaster has enough force and acceleration to go around the loop. 6. After making the initial adjustments, try the ride again. Continue making adjustments until the ride becomes successful (rider makes it from one end to the other completely – does not have to make it back through). 7. Raise your hand and show the teacher your successful design. 8. Draw a side-view sketch of your successful design below. 9. Label the points of acceleration on your sketch. a. Down arrow = slowing down b. Up arrow = speeding up c. Circle arrow = changing direction 10. Click the “Track Friction >>” button and adjust the setting. 11. Run the rider through your track again and observe the changes. a. Did the rider make it to the end? Yes, the rider made it to the end. b. What do you notice differently about the pie chart and/or bar graph? It has more thermal energy. 12. Describe the changes you need to make to your design, as a result of the presence of friction. I would have to adjust the placement of the loop and drop to get a lot of acceleration. 13. Make the necessary adjustments until you achieve a successful ride with friction. 14. Raise your hand and show the teacher your friction-savvy coaster. 15. Draw a side-view sketch of your friction-savvy coaster below. Before After Post-Lab Questions: 1. List and explain the differences between each of your sketches. On the first sketch the loop came before the drop which did not give the roller coaster enough acceleration to go around the loop. On the second sketch I put the drop first and then a couple of turns and then the loop which worked but when friction was present it was increasingly difficult for the roller coaster to make it around. On the third sketch I put the drop then the loop and then the curves and turns which helped lower the acceleration the roller coaster got from the drop and the loop to finally end the ride. 2. At the top of a hill on the ride, most of the energy is __Potential energy___ and at the bottom of the hill, most of the energy is converted into __Kinetic energy______. 3. What are the equations for potential and kinetic energy? Potential: P.E = mgh m = mass in kg, g = acceleration due to gravity, and h = height in meters. Kinetic: K.E = 1/2mv2 m = mass in kg, v = velocity of meters per second. 4. If you were an engineer of an actual roller coaster, what information would you need to know in order to ensure that your coaster would be safe? That the speed is at a durable pace and that the brakes work. Also, that the roller coaster does not just stop somewhere. 5. Would it be possible to predict the speeds that a coaster will reach before it’s ever placed on the track? How? Yes, it is possible to predict the speed that a roller coaster will reach before it is placed on the track because as potential energy switches to kinetic, you can solve for the velocity. 6. The most thrilling roller coasters usually contain vertical loops. What keeps the riders in their seats when they go upside-down? Centripetal force keeps the riders in their seats. Its inertia presses the rider’s body to the outside of the loop as it spins around. 7. Consider going around a horizontal turn to the right. If the coaster suddenly slipped off the track, what path would it follow? Draw a top-view sketch below. 8. You should have drawn the coaster following a straight line after it slipped off the track. Since that is the path it would take without the track, there must be an unbalanced force causing it to accelerate (turn) around the bend. What direction is that force pointing? Draw a top-view sketch of the force vectors below. The force is pointing perpendicular to the turn.