The Physics of Sports

The Physics of Sports

Basketball

How cool is it when a basketball player looks suspended in the air when shooting a 3-pointer or going for that dunk. This is actually a consequence of projectile motion in Physics. When an object is thrown in the air, it will spend a large percentage of time in the top part of the throw. This is what happens when a basketball player jumps. A basketball player can jump as much as 4 feet (120 cm) in the air vertically. The higher he or she jumps, the greater the hang time (the total time being airborne).

The backspin technique is also frequently used in a basketball game. In order to increase the chances of getting the ball into the net, players tend to bounce the ball off the backboard or the back of the net. This backspin technique is based on the fact that when an object is spinning and bounces off something, it has the tendency to bounce in the direction of the spin. Using this trick will more likely send the ball downwards into the net. Without the backspin, the ball is more likely to bounce away from the net.

Baseball

Baseball players are constantly striving for hitting the “sweet spot” – the location of the baseball bat regarded as the best spot for hitting the baseball. At this spot, vibration of the bat is minimized, resulting in the maximum amount of energy being delivered to the baseball for it to travel the farthest. This sweet spot is also a special point on the bat which minimizes stinging of the hands when the ball strikes. Baseball players say that hitting the ball in this location feels the best, resulting in the most solid hit. When the ball is not struck on the sweet spot, the player can sense a painful and stinging sensation on the hands due to bat vibration. This vibration energy also causes a loss in energy that is being delivered to the ball. As a result, the ball does not travel as far.

Long Jump

Most people think that long jump is simply an attempt of running very fast, followed by throwing yourself in the air and hoping for the best at the end. This is not the case. For long jumpers, their aim is to land their legs as far as possible in front of their bodies. The tricky part comes when they have to radically change the position of their legs from the back to the front whilst in mid-air (when they are airborne after the jump), without drastically changing their moment of inertia (the distribution of your mass around your centre of gravity). It is a basic law of Physics that your angular moment (the momentum your body has because it’s rotating) cannot increase or decrease. The way to achieve this is to use your hands. As one shoots the legs forward and outward, throw the arms upward and bring them down quickly. As your arms shoot back, your legs shoot forward in mid-air to compensate or to ensure the conservation of angular momentum.

Sprinting

How can someone like Usain Bolt run so fast? Based on Newton’s second law of motion, you can make a mass accelerate or gain speed by applying a force to it. Hence you can give something more momentum by applying a force to it for a certain amount of time (also known as an impulse). To make yourself run faster, you must have the ability to deliver impulses with your legs that accelerate you faster. But the bigger in size you are, the more force you need to accelerate it. Once your ability to generate powerful impulses to your legs to gain acceleration outweighs or exceeds your mass, you can sprint faster.


Read about Physics in the Kitchen.