Ski Jump: Are You Flying or Falling In Style?

If we both take a leap at the highest possible height you and I can remain off the ground for approximately one-half of a second. Michael Jordan could stay aloft for nearly a second. There are a myriad of occasions during the Winter Olympics that feature athletes doing feats of athleticism or endurance while in the air however no event can blur the lines between flying and jumping nearly as much as the ski jump.

I train students in the physical physics behind sports. A ski jump can be among the more fascinating activities at the Winter Games to showcase physics in motion. Winners are the one who is the furthest from the ground and who jumps and land in the most elegant manner. Through transforming their bodies and skis into the wing of a ski the ski jumpers are able to defy gravity and remain in the air for between five and seven seconds while traveling approximately an length of an football field in the air. How do they accomplish this?

How To Fly

Three fundamental concepts of physics are in play in the ski jumping three major concepts from physics: drag, lift, and gravity.

The force of gravity pulls objects that is flying towards the ground. Gravity affects every object equally, and it is impossible for athletes to do to reduce its impact. However, the athletes also interact with air when they move. This interaction can result in lift. Lift is a force that goes upwards produced by the force of air on the object. If the force generated by lift is in some way balanced with gravity’s force the object will glide or even fly.

To generate lift, the object has to move. As the object travels in the air, its surfaces interacts with air particles, and forces these particles away from its path. When the air particles push back down and the object is then raised according to Newton’s Third Law of motion which states that for each move there is an opposite reaction. Air particles pushing objects upwards create lift. Speed increases and expanding the area of the object will boost the quantity of lift. It is also important to consider the Angle of Attack is that is the angle the object in relation towards the direction in which flow of air can affect the lift. If it is too steep, the object may stall, or too low and it will not push downwards on the air particle.

Although it may appear complex, sticking your hands from a car’s window demonstrates these concepts perfectly. If you keep your hand flat it will remain mostly in the same position. If you turn your hand to ensure that the your bottom is facing towards the direction of wind your hand will move upwards as air particles collide with it. This is known as lift.

The same collisions that occur between an object and the air that create lift also cause drag. Drag blocks the movement of an object, and it reduces its speed. When the speed slows down, lifting will as well, limiting the duration of an air flight.

Ski jumpers’ aim is to employ a careful body position to maximize lift while decreasing drag as much as is possible.

Skiing In The Air

Skiers get up high on a slope, then they ski downhill to gain speed. They reduce drag by kneeling down and carefully steering to minimize friction between their skis and the ramp. At the bottom, they are traveling at sixty miles an hour (96kph).

The ramp is finished at a point of takeoff that is, if you take a closer look you will see that it actually has an upward slope of about 10-degrees. When the athletes get to the top of their ramps, they leap. The landing slope on the skis is designed to replicate the steps a jumper might make so that they’re not more than 10 or fifteen meters over the floor.

When the athletes are up in the air, the excitement of physics begin.

The athletes do everything they can to generate the most lift they can while minimising drag. The athletes are not capable of generating enough lift to completely overcome gravity however the higher their lift the faster they’ll fall, and the further up the hill they’ll travel.

For this, athletes place their body and skis in line with the ground. They then position the skis into a V shape just away from the body. This will increase the surface area that produces lift. It also places them at the perfect angle of attack to increase lift.

When drag decreases speeds of skiers, the lift diminishes and gravity continues pulling on the skier. The athletes will fall faster and faster until they reach their destination.

The rules are based on physics. With so many physics at play there are lots of ways that wind or equipment selections, and even bodies of athletes could affect the distance the jump will go. In order to ensure fairness and secure, there are a number of rules.

When you are watching the event there is a possibility of officials shifting the starting point either up either down or up. This is done in accordance with the speed of the wind because faster headwinds can create higher lift and lead to longer jumps, which could extend over the safe landing area.

Ski length is also restricted and is based on a skier’s weight and height. Skis are allowed to be 145 percent of a skier’s height and those with an index of body mass less than 21 should have shorter skis. Skis that are long aren’t always ideal as the heavier you ski, greater lift you’ll need for you to remain in the air. In addition, skiers need to wear tight-fitting clothes in order to make sure that they don’t use their clothing to provide additional lift.

While you are watching the Olympics to be amazed by the strength and power that the competitors display, be sure to think about their understanding of the theories of physical science.