As expressed in the Homepage, the objective of this demonstration is to discuss the effects of Newton's Law of Motion and Centripetal Force.
We often see these two concepts of Physics taught and used in a singular dynamic. An object follows Newton's Second Law of Motion with a final magnitude and direction. An object has centripetal force as long as it travels in a circle. However, these physical properties often occur together (though not simultaneously).
Another objective is to provide the students a visualization of different concepts of physics that occurs when someone is driving. When a car accelerates from rest, the car follows Newton's Laws of Motion. As the car reaches a position to turn, it results in some form of circular motion. If the car needs to turn right, the car will travel a quarter of a circle. If the car does a U-turn, it willl travel half of a circle. The image below was taken from the PowerPoint to discuss the uses of both external and centripetal force (in both regular turning, and drifting manoeuvres).
The following is the lesson plan:
1. Simple History Talk a little about why drifting was used. There were two great drivers who influenced the world with drifting: Kunimitsu Takahashi and Keiichi Tsuchiya. The great Kunimitsu used this technique to win a lot of his championships back in the 70s. While Keiichi took drifting to the mountains in Japan. Later, drifting a prime staple to those who raced in the very same Japanese mountains. 2. Provide some video representation of drifting One of the best ways to draw students attention is to show them video clips of something they may be familiar with. In this case, there are three representative videos that help with visualizing drifting. One from the movie, Fast and Furious 3: Tokyo Drift, another from the movie: Cars (presented by Disney Pixar), and one from a Japanese Animation called, Initial D. You can find the following on YouTube, Parking Lot scene in Fast in Furious: Tokyo Drift and Hudson Hornet drifting. 3. Discuss these very important Disclaimers Drifting is indeed illegal on the streets; unless performed accidentally or within reason. One should not perform or use this manoeuvre intentionally. However, you may do these activities with a professional at designated drifting/racing tracks. Another way to drift is through remote controlled cars. There is a large community in remote racing! 4. Talk about why someone might drift Note that drifting is not necessarily faster or slower than regular turning (in more of a racing definition). However, drifting has its benefits. Drifting allows an individual to enter into a turn faster, accelerate out of the turn faster, and block off some of the road such that others cannot overtake during the turn. Another reason to drift is for roads with immediate changes in direction. These roads are often seen in mountains. These roads may make multiple U-shape-like turns consecutively, allowing drifting to be quite efficient in terms of a race. Lastly, drifting is especially useful for roads with less traction, these are often seen in Rally Racing. Low traction means there is not a lot of grip between the tires and the ground, an example of that is driving on icy roads or dirt roads. Less traction means the more the car is able to slip its tires. Here we should also discuss about the types of turns that cars may encounter. These include increasing/decreasing radius, chicane, and the infamous, hairpin (180 degree) turn. 5. Go through the Physics Announced earlier, there are only two concepts in Physics that will be discussed: Newton's Laws of Motion and Centripetal force. There are three Newton's laws, inertia, force, and action-reaction. Inertia relating to objects remaining at rest or in uniform motion in a straight line unless compelled to an external force. Force is the basic F=ma equation that everyone loves. And lastly, action-reaction is the law describing that when there is an external force acting on the object, there is an equal in magnitude but opposite in direction reaction. Centripetal force is not derived, but the concept and the equation is important for this demonstration. Students need to understand that as long as an object travels in a circular path (but not necessarily the entire circle) will have centripetal force. The two physical properties are combined to allow a car to perform its duties around a given track/road. 6. Show a simple Centripetal demonstration Using some sort of light mass on a string (like an ornament on a string), a simple representation of centripetal force can be displayed. When held at the opposite end to the ornament, and spun using the hand as the pivot point, the ornament will create a circular after-image of itself. This concept is related back to in a later part of the lesson. 7. Onto the physical demonstration of drifting Because the track is created on a horizontal plane, it may not be very visible for all of the students to see when demonstrating live. I came up with the idea of using multiple angles in a compilation video so that all the students are able to see. That very same video is constantly looping in the homepage. After this short compilation video, it may be best to show some birds-eye-view angles to maximize understanding. 8. Applying the Physics to the demonstration Need to put the concepts together with the demo. In summary, as a car accelerates, the engine (the electric motor in the RC car) generates an external force forwards. As a car enters a hairpin turn, it will follow a circular path. ** Note that, whether a car turns normally or it drifts, the car is able to turn in the same circular path as long as it travels the same distance from the center. However, because drivers who drift can enter turns at a higher velocity, it will result in a higher centripetal force. The main difference between regular turning and drifting is the velocity which the car travels at during the circular motion. No matter how sharp the turn is, or how much it changes in shape, cars that will drift have higher speeds. This does mean there is a trade off between the two styles of turning. Regular turning means you will need to slow down on entry, but this also means it is safer. While drifting sacrifices safety for high entry speed, which can highly reduce the radius of the turn. Both styles of turning will allow you to accelerate out of the turn fast. In the end, neither turns are faster than the other, the most that drifting can provide is how cool it looks. 9. The Take Home message Physics is applicable to everything! Newton's laws of motion is not restricted to simple objects, in fact, many of these ideas stemmed from complex objects. Turning a complex human shape into a point with a mass to simplify calculations is common practice. Centripetal force occurs in many motions and dynamics. When someone is driving, centripetal force occurs at every single turn, despite the fact that some of the turns may be 90-degrees, 30-degrees, or 180-degrees. It is also prevalent in other situations such as when the toilet flushes! Lastly, drifting is cool, it looks cool, it has benefits such as blocking people off, but in the end, it is not that much different from regular turning.