Athletes on the Physics Behind Jumping

By Ellie Chen

Jumping is an essential component in many sports. Some sports are solely based on how high or far an athlete can jump, and other sports rely on jumping to help athletes gain a better position than their opponents. But how does physics play into jumping? And how can student athletes use physics to their advantage?

A Focus on Solely Jumping

In the cases of the long jump and triple jump, an athlete’s goal is to jump as far as possible. In order to do so, the athlete’s vertical and horizontal velocity must be taken into account. Velocity is speed with a particular direction.

The athlete’s horizontal velocity determines how far the jump is. Therefore, running before the jump to gain speed is very important. The faster the athlete is before the jump, the farther the athlete can travel during the jump.

The vertical velocity attained by the jumping motion plays a big role, as the larger the vertical velocity gained by jumping, the longer the athlete stays in the air, which allows more time for the horizontal velocity to help the athlete travel a farther distance.

According to Real World Physics Problems, another way to increase the distance of the jump is for athletes to raise their legs right before they land because in doing so, they are increasing the vertical distance between the highest point of the jump and the landing. This will result in  longer jump time and therefore an increase in the horizontal distance travelled, since velocity equals the change in position over change in time.

Most athletes use the Fosbury Flop technique when doing the high jump. Using this technique, the athlete jumps backwards over the bar. According to Scientific American, this technique is often used because the speed of the jumper is determined by the height of the person’s center of gravity, and this jump keeps the athlete’s center of gravity close to the ground. Therefore, the athlete is able to jump higher.

The Role of Jumping in a Variety of Sports

In many sports, the role of jumping is less obvious compared to the sports mentioned previously. One of these sports is volleyball. In volleyball, players jump up to hit the ball over the net and onto the opposing team’s side of the court. A higher jump can benefit players because it allows them to manipulate the trajectory of the ball to their advantage by hitting the ball at a higher point above the net. By doing this, players can focus on making a hard hit rather than trying to get the ball to go over the net.

Junior Anusha Pothineni is an MVHS varsity volleyball player.

“I was always told to squat low right before taking off so that I would be more explosive and that I should jump off my toes,” she said. “And I should make the last two steps of my approach faster to make my vertical higher and more explosive.”

While Pothineni has been taught certain techniques, she said none of her coaches “told me why it was important scientifically.”

Junior Alicia John, also an MVHS varsity volleyball player, stated that she has been told to “speed up in the last few steps of the approach before jumping.”

The effectiveness of their jumps are directly related to one physics concept: power. Power is force multiplied by velocity.

The force in this concept is related to the strength of a person, which explains why athletes often use conditioning exercises; it gives athletes more strength. By making the last two steps of their approaches faster, they increase their velocity and therefore increase their overall power.

So by increasing speed before jumping and training to develop more strength, athletes can jump higher and be more successful in their performance.

A common view shared by both athletes is that the physics behind jumping was never really explained to them.

“I think that would make athletes understand why the things they are told to do work, and that will make them see the value of those techniques more,” John said. “It will also help them be more conscious or aware of their movements and help them improve.”

“I feel like it would be helpful for more analytically driven people like me,” Pothineni said.

Both volleyball players feel that having someone explain the scientific reasoning behind why they are told to use certain techniques would benefit athletes.

A More Obscure Look at Jumping

Another sport that has a more implicit use of jumping is swimming. While the majority of swimming happens while athletes are in the water, swimmers start above the water on diving blocks. They push off the blocks and enter the water. The initial push is very important because it affects how each swimmer starts. For example, if one swimmer pushes off more effectively than another swimmer, they have an instant advantage.

Junior Alice Cheng is an MVHS varsity swimmer.

“He [our coach] always tells us how the fastest people get into a really good streamline and use their legs to push off the blocks and also create the least splash,” Cheng said. “That’s why they’re the fastest at the initial underwaters.”

Pushing off the diving block is also an example of power (force times velocity). By using their legs to push off the diving blocks, swimmers can maximize their strength, which contributes to the force in the power equation.

It seems that while athletes are often taught to do certain things to improve their performance, they are not actually told why they work. If coaches implement physics into their coaching when explaining why certain techniques are effective, athletes would be more likely to understand why they work.