Section One: Reaction Time
- This concept of reaction time relates to driving because it affects your safety in many ways. While driving, there are a lot of situations in which the outcome depends on your safety. For example, if you are driving and a deer runs out into the middle of the road, you will have to quickly react to avoid hitting the animal. In addition, you will need to quickly react at an intersection if a light turns red and you have to stop. We now know to stay focused on the road and not be distracted so we stay safe.
Section Two included information about measuring anything that could include precision, accuracy, and error. Precision is an indication of the frequency with which a measurement creates the same results. Accuracy is an indication of how close a set of measurements are to a value. Two types of errors are systematic and random. Systematic errors are when a wrong measuring tool was used but can be corrected by changing your mistake with the tool. On the other hand, random errors cannot be corrected because the measuring tool or the person wasn't precise. Measuring is very important when driving on the roads.
I need to know this to be a safe driver because measuring will help me greatly as I come into the world of driving an automobile. When I need to see how precise or accurate my speedometer is I can use my measuring experience to figure out my speed by measuring the distance between mile markers. Also, approaching an accident or light my measuring can assist me into making decisions of when to slow down or when to speed up. Measuring is key to decision making and finding values when driving.
We learned that there are three main ways to describe speed -- strobe photos, graphs, and an equation. A strobe photo is a combination of multiple pictures taken at set intervals of time that are grouped together in one picture. A strobe photo can be used to determined a constant speed, or acceleration. We learned to graph speed on a distance-time graph. We did this by placing points on a graph in their relation to how far a car has traveled in a certain amount of time. Lastly, the equation used for speed is distance divided by time. This is an easy method to use to calculate speed if you have both variables.
Learning about describing speed has helped us become safer drivers overall because it keeps us aware of cars in front and behind us. In this lesson, we also were taught about following distance. You must stay at least one car length behind another car, but it is preferred to stay more. This is very important especially if there are bad road conditions or other factors affecting the quality of your driving.
In this section we learned how changes in speed or direction, called accelerations, are related to time and distance for a moving vehicle. We also interpreted distance-time and velocity-time graphs for different types of motion.
Acceleration = Change in Velocity / Change in Time
Acceleration is the change in velocity with respect to a change in time. Acceleration is also a vector quantity meaning it has both magnitude and direction. There are two different types of acceleration, negative and positive, which both depend on the change in speed during the period of time and the direction.
In this section we designed an experiment to investigate negative acceleration and stopping distance. We also used friction as your brakes and measured the stopping distance for different starting speeds to compare speeds and stopping distances. Negative acceleration is a change in velocity with respect to time of an object by decreasing speed in the positive direction or increasing speed in the negative direction. However negative acceleration doesn’t necessarily mean slowing down in physics terms. Acceleration depends on direction and change in speed.
The Go, Stop, Dilemma, and Overlap Zones are all areas in where a car can be positioned to see their state of safeness can be determined. The Go Zone is where an automobile can safely travel through the intersection. To calculate the zone use the equation, GZ=VTy-W. In contrary, the Stop Zone is the area where a vehicle would not safely make it through the intersection and should slow down when the yellow light comes on. The equation to find the stop zone is SZ=VTr + V^2/2aA. The Overlap Zone is where the driver can decide whether or not they want to travel through the intersection. However, the Dilemma Zone is where a vehicle can't safely stop at an intersection or travel through. These zones are very important in the world of driving.
Knowing about all these different zones will give drivers a safe understanding of how to handle situations at yellow lights. Many drivers don't know what to do at a yellow light but figuring out the basis of equations the decisions will be easier. I also used models in this section to show intersections which will allow me to visualize where I will be safe now at intersections.
Centripetal force is a force directed toward toward the center to keep an object in a circular motion. This, along with frictional force, attempt to keep the car on the curve of the road. Velocity, on the contrary, is facing straight so the car wants to follow this, resulting in going off the cliff. The two forces pull the car towards the center so the car can grip the road and continue on the curve.
This helps me to be a safe driver because without centripetal and frictional force, the car would go straight off the cliff if you don't turn the steering wheel fast enough, or slow down quick enough. This also helps me become a safe driver because I will realize how the forces operate so I will know how to slow down quick enough and stay on the curve.
In conclusion, we know how to be safe drivers in the future by learning from these various sections. From sections 1 through 7, we have learned reaction time, measurement, average speed, graphing motion, negative acceleration, models, and centripetal force. These things combined give us knowledge about how to handle road situations and the physics behind it. We hope that you realize that we will use what we learned to graduate the active driving academy.