Kosuke+and+Rob


 * ACTIVITY A: The First Drop of a Roller Coaster **

Name of any roller coaster ride: Nitro

1) Estimate distances and angles and 2) Measure Time 3) Diagrams a. FBD of car on a) the way up, b) on the way down, and c) at the bottom of the first hill.
 * PART A) At the park **

b. FBD of mass on a string at a) on the way up, b) on the way down, and c) at the bottom of the first hill c. Labeled sketch of relevant portion of the roller coaster (top and side views)  d. Take a clear side view picture  e. Take a short video of the relevant segment for future reference @http://www.youtube.com/watch?v=LW60JEEv3ZQ
 * These FBDs are relative to the ground, not the car. The weight and tension forces are always perpendicular to the ground.

4) Graphs a. Create d vs. t, v vs. t and a vs. t graph for the motion this segment of the ride.  b. Create a thrill vs. acceleration graph for this segment of the ride.

5) Evaluate a. Safety: What features were in place? The only feature to protect the rider from falling out of the roller coaster was the unobtrusive lap T-bar that latched the rider into place. There was nothing to hold onto, which contributed toward the sense of vulnerability. b. Describe the weight sensations on the way up, on the way down, and at the bottom of the first hill: did you feel lighter, heavier, or normal? On the way up, there was really no different weight sensation... only the building suspense about the fear of death. It was a slow trip up. On the way down, I felt like I was being held down only by the T-bar (I felt lighter); I felt like I was nearly weightless, and thus felt a funny feeling in my stomach. As I neared the bottom of the hill, I felt like I was cemented to the bottom of my seat. c. Describe the excitement level: on the way up, on the way down, and at the bottom of the first hill. On the way up, I was very nervous and scared. On the way down, I was screaming my head off and laughing; it was so fun and so fast, though there was a bit of fear mixed in. It was very exciting. At the bottom of the first hill, I was a bit less excited because I had just gone past the biggest drop, but I was too busy being crushed to my seat that I really didn't care. It was one of the best, exciting moments of my life. d. Describe the thrill factors that may contribute to those feelings (besides the #g’s) One thrill factor was that on the first drop, I couldn't even see the tracks under the coaster due to the steepness. I was also in the front car, which is where the most "airtime" and other sensations are felt. It was also difficult to see where the coaster was headed. Perhaps the biggest thrill factor was the anticipation at the top of the first hill, peeking down the giant hill and seeing the massive, steep drop.

Data Table: 1) Calculate Experimental Values a. Speed at bottom of the first hill  b. Acceleration down the first hill  c. Power needed to get up the hill
 * Part B) Back at School **

2) Calculate Theoretical Values a. Speed at bottom of the first hill  b. Acceleration down the first hill  c. Power needed to get up the hill

3) Evaluate Accuracy of the 3 calculations above. Clearly, our results are not very accurate, but there are legitimate reasons for this. Nitro was closed, so we couldn't get an accurate reading of the time it took for it to drop fully. In addition, when timing, we did not have a clear view of the bottom, so we could not see the exact point at which it hit the bottom of the hill. This would skew our experimental results horrendously, leading to the percent differences you see here. There would also be a bit of error from friction and air resistance.

4) Evaluate Safety a. Calculate #g’s on the way down the hill and at the bottom of the hill  b. Were #g’s within safe limits?  Yes, as they are low enough for humans to safely experience them without dying, which is 4-5 g's. It was close enough to 9.8 m/s^2 to make the rider feel exhilarated.  c. Was there correlation between #g’s and excitement level? Explain, providing evidence. As the # of G's went up, excitement increased as well. As acceleration increases, the g's increase as well, and according to our amazingly scientific acceleration vs. thrill graph, there is a direct relationship between thrill and acceleration. Therefore, as g's increase, excitement does as well.

5) Thinking about Physics a) Explain the behavior of the mass on the string. Did the FBD of the car correlate to that of the mass? Why or why not? No because the forces acting on the car are at different angles. For example, on the way up, there is a tension force pulling towards the top right, a normal force perpendicular to the tracks, and weight force straight down. The FBD of the mass on the string, however, is not influenced by normal force at an angle. The only two forces are Tension from the person holding the string and weight straight down. Excluding friction (or air resistance), the mass on a string should remain perpendicular to the ground (not the tracks) at all times because there is no other force to make it move. b) Did the #g’s correlate to the sensation of weight? Yes they do. Having a high number of gs makes you feel heavier than you really are - and conversely, having a low number makes you feel more weightless.  c) Discuss the graphs that you created and why they curve the way that they do. The distance vs. time one goes up at a constant slope, showing the constant speed we felt as we went up. However, we then fell drastically, as seen in the very steep drop in our graph. Directly after, we went back up, and the line does the same. The velocity vs. time graph is level at first because of constant velocity. We then felt a crazy acceleration due to the very steep drop, and this is again represented in the graph. Our velocity shot through the roof. The acceleration graph is zero at the beginning because of constant speed. After the drop, it rises to a higher level to show the constant acceleration we felt as we were going down nitro's hill. The acceleration vs. thrill graph is pretty self explanatory. As acceleration went up, our thrill went up because we thought we were about to die from the crazy speed. Luckily, we didn't.


 * PART C: A Rotating Ride (either Vertical or Horizontal) **

Name of any rotating ride: Carousel

1) Estimate distances and angles and 2) Measure the period. (Data tables)
 * PART A: At the park: **

3) Diagrams a. FBD of car or rider (at max and min height, if vertical).  b. FBD of mass on a string at various positions (at max and min height, if vertical).  c. Labeled sketch of ride (top and side views)  d. Take a clear side view picture

e. Take a short video of the relevant segment @http://www.youtube.com/watch?v=n9dR10X0O9M

4) Graphs a. Create Fc vs. t and a vs. t graph for the motion this segment of the ride.  b. Create a thrill vs. acceleration graph for this segment of the ride.  5) Evaluate a. Describe the safety features of this ride. The only safety feature was a strap/seatbelt that was supposed to go around the waist. Since the ride was so slow, there really was no need for a safety feature. Many adults rode with their young, so they prevented the very young children from falling off. b. Describe the excitement level that you felt at the min and max height (if vertical), or at max speed (if horizontal) It was a pleasant ride, but soon became boring and was not exciting in the least. c. Describe the thrill factors that may contribute to those feelings (besides the #g’s) There really were no thrill factors. d. Describe the weight sensations at the top, side and bottom of the loop.: did you feel lighter, heavier, or normal? There was no loop. The only change in weight sensation once the ride got started was that I was tending to fall outward off my horse a little bit.

1) Calculate Experimental Values a. Average Speed  b. Centripetal Acceleration  c. Apparent weight  2) Calculate Theoretical Values -We found a website that gave the rpm of the Carousel at Six Flags GA. rpm=4.5 []
 * PART B) Back at School **

a. Average Speed

b. Centripetal Acceleration

c. Apparent weight

3) Evaluate Accuracy -Velocity:

-Acceleration:

-Apparent Weight will stay the same b/c there is no acceleration in the y-axis at all. Thus, 0% Error.

Summary: -The percent errors we got for this ride was not under the 10% mark that we often use to measure accuracy. However, this is due to a myriad number of reasons. The main reason is that we could not possible take down perfect results using a hand timer; we had to eyeball approximately one revolution. Also, we tried to use only the results from when the ride was going at full speed, but at the beginning and at the end some of the periods were not totally up to speed. Finally, we were on the ride itself while timing, which caused further difficulty in maintaining accuracy (I was getting a little bit dizzy, hard to determine exactly the beginning and endpoint of a revolution when you're spinning, etc.).

4) Evaluate Safety a. #g’s  b. Was there correlation between #g’s and excitement level? Yes. This ride was made for people who don't like rides. Thus, it is really not very exciting. This is easily seen in the number of gs, which is pathetically low.

5) Thinking about the Physics a) Explain the behavior of the mass on the string. Did the FBD of the person correlate to that of the mass? Why or why not? No. The tension acting on the mass had to compensate for the rotational by tilting a little bit, creating some x-force to create centripetal force. That tension acting on the x-axis corresponds to the Normal force (centripetal force) acting on the rider to keep him on the ride instead of toppling off the outer side. b) Discuss the graphs that you created and why they curve the way that they do. For the force vs. time graph, the force increases as the ride accelerates to maximum speed. When it hits its highest speed, it maintained it, leading to the same value for a while. Then, as it slowed down, it decreased.This is the same for the acceleration graph. The thrill graph gets has its shape because our thrill goes up as it speeds up, and then goes down as it slows down. The top is the point at which we realize its not going any faster, so we just get disappointed and thrill goes down.

Activity B: (not needed)
 * ACTIVITY B: A Vertical Loop of a Roller Coaster **

*For the third ride, just present your collected/researched data and observations, but you do not need to do any analysis.*

Name of any roller coaster ride: Batman

1) Estimate distances and angles and 2) Measure Time for a single car to pass through the top of the loop.
 * PART A: At the park: **

3) Diagrams a. FBD of car or rider at top position  b. FBD of mass on a string at top position  c. Labeled sketch of roller coaster (top and side views)

d. Take a clear side view picture []

e. Take a short video of the relevant segment @http://www.youtube.com/watch?v=QmKLfutZuOo skip to around 2min for ride

4) Graphs a. Create v vs. t, Fc vs. t and a vs. t graph for the motion in this segment of the ride.

b. Create a thrill vs. acceleration graph for this segment of the ride. 5) Evaluate a. Describe the safety features on this coaster There were over-the-shoulder restraints and a safety strap to keep the rider strapped onto the seat at all times. Unfortunate accidents have only occurred when people were hit by dangling objects in the danger zone under the roller coaster, not because of safety feature malfunctions. b. Describe the excitement level that you felt at the top, side and bottom of the loop.  The top of the roller coaster was the most exciting because we lost a lot of speed and thus felt less apparent weight. The way up was kind of exciting, while the way down was more thrilling because we gained lots of speed.  c. Describe the thrill factors that may contribute to those feelings (besides the #g’s) One thrill factor that contributed to our excitement levels was the fact that we were inverted: on the way up, we say the sky, at the top we say the horizon upside-down, and on the way down we saw the ground without seeing the coaster railing at all (felt like we were falling down). d. Describe the weight sensations at the top, side and bottom of the loop.: did you feel lighter, heavier, or normal? We felt lighter at the top of the loop, a little bit heavier than normal on the sides, and much heavier than normal at the bottom of the loop.

Part B: 4) Thinking about the Physics a) Explain the behavior of the mass on the string. Did the FBD of the car correlate to that of the mass? Why or why not? Yes they did. One force went upward, while the other force went downward. However, the types of forces were different. b) Did the #g’s correlate to the sensation of weight? Yes, they did.  c) Discuss the graphs that you created and why they curve the way that they do. For the velocity time graph, the speed drops significantly as you enter the loop, and then increases as you drop down the other side. Thus, it forms a V shape. The centripetal force acts in much the same way. It increases when velocity does, and decreases when velocity does as well. Thus, it follows the same general shape, though it is more rounded due to the nature of circular motion. The acceleration graph looks like a staircase because we were slowing down as we entered the loop, and sped up as we left it. The thrill vs. acceleration graph shows that as we accelerated, we became more thrilled with the ride. This is because of the risk that high acceleration makes us feel.

ALL Positions CITED FROM: []
 * (**New 2012 Physics Workbook - Now Includes Green Lantern)