Air resistance is usually calculated using the “resistance equation,” which determines the force experienced by an object moving in a liquid or gas at a relatively high speed. This can be expressed mathematically as follows: the faster the vehicle moves, the greater the air resistance. I think calculating drag is important for car designers. If you make a vehicle aerodynamic, it encounters less resistance. Many vehicles have smooth bends, so they go faster. For example, if a parachutist falls into the air, the air resistance acts against his fall. So we draw an arrow pointing upwards, as shown in the image below. Water resistance is stronger than air resistance. Animals that move quickly in the water need to be rationalized. That`s why fish are all rationalized. Their smooth, round heads and long, tapered bodies allow water to flow more easily in front of them.

For things to move efficiently through air or water, they need to have the smallest surface area possible. Because the larger the area, the greater the resistance. Therefore, things need to be streamlined to push against air or water. Indeed, the resistance depends on the type of flow. Turbulent flows are known to be fast and require the use of (vec{v}^2), while laminar flow is slow and uses (vec{v}). Since the terms “slow” and “fast” are relative, a dimensionless quantity known as the Reynolds number must be considered, where low values are correlated with laminar flow and high values with turbulent flow. Real-world examples such as skydiving and blood flow in our arteries are high-speed events and would therefore require the use of (vec{v}^2). Unfortunately, such a thorough drag analysis goes beyond the physical level AP, so we will consider drag linearly in air velocity. For example, if you run fast, you will feel the air pressing against your body. The faster you move, the more air resistance presses against you. I`ve always been a little confused by the definition of drag. It amazes me that even if a person would experience more air resistance than a leaf, if both fell from the top of a building, the human would fall to the ground long before the leaf.

First, we will look at how the surface of an object affects the air resistance to which it is subjected. Option A is therefore correct: a larger surface area creates more air resistance. Humanity has always been able to observe the effects of air resistance, but the physical factors were not understood until the 17th century. Galileo, trying to understand the principle of gravity, used experiments to test Aristotle`s thesis that heavier objects fall faster than lighter ones. He was able to prove that this was not true; The gravitational force acts on each object in the same way. He realized that lighter objects were slowed down by air resistance, and heavier objects had enough weight to counter this factor. Air resistance always tries to slow down a moving object. Air resistance and gravity are nature`s two built-in forces that act on everything that is lifted off the earth and moved by the air.

When a parachute has a larger surface area, more air presses against the object and it experiences greater air resistance. The larger the area, the greater the resistance. By understanding and modifying the factors that influence air resistance, we can control air resistance between objects and air. A spring that falls to the ground tends to float and move slowly, rather than falling in seconds like other objects of slightly higher mass. Gravity pulls the spring towards the earth; However, the drag prevents the spring from falling or moving during movement. Aircraft are designed to overcome air resistance, called air resistance in the field of aerodynamics. The sleek design of most jets and rockets allows them to pass through the atmosphere with as little drag as possible. Cars and trains also use simplified designs to a lesser extent for the same purpose. Unless they are designed for high-speed travel, drag is not as much of an obstacle for ground vehicles as it is for airplanes.