Center of Gravity

The center of gravity is the point in an object where all the objects mass is concentrated. It's also the rotating point of any object. If you throw an object, it will always rotate around a certain point. That point is it's center of gravity. The center of gravity most commonly lies in the center of a symmetrical geometric shape. In order for humans to stand without falling over, there is a fixed line that travels up through the middle of your feet, through your center of gravity, and through the top of your head. If your center of gravity travels away from this fixed line, you will lose your balance and not be able to stand up. Balance is a big part of your center of gravity. Your center of gravity is the one point where all the balance points in your body lie. There are multiple tests you can do to find your center of gravity, but in most people your center of gravity lies in your lower abdomen area, which is right where your geometric center is located. Another interesting fact about the center of gravity is that, in a machine with many moving parts. It's center of gravity can change as the parts inside of it move around.

Wall Bend

Have you ever tried to stand straight against a wall, then try to pick something up from the floor in front of you without letting your legs leave the wall? If you have, you will notice this is not possible. The reason that this isn't possible is due to something called "Center of Gravity". Your center of gravity can change when you make different positions and when you are either rapidly moving or dancing. When your body is standing straight against the wall, your center of gravity lies in your lower abdomen. As you bend over, your center of gravity shifts from your lower abdomen to the outside of your body, located right outside your stomach. Due to this shift of gravity your body loses it's balance and you fall or stumble to regain your balance.

The Fork Balance

This experiment, as well, relies on the center of gravity to explain how it works. The center of gravity is where an object can balance from left to right, front to back, and up and down. You might notice, the balancing point (pivot point) is actually located right in the center of where the two forks handles are located. In almost all objects, the center of gravity is located in the between the two areas of the object that has the most mass. If the two areas with the most mass are the same weight, then the center of gravity is located directly in the center of the two masses.

Bird Balance

The center of gravity is commonly explained as, "The point of which all the mass of an object appears to be concentrated." In this example there are two weights located in the tips of the birds wings. Those weights in comparison to the rest of the birds body creates a "concentrated mass" for the object. The center of gravity lies in the mid-point of the area in between them. Which, in this case, lies in the birds beak. Without the weights, the center of gravity is located more behind the beak and is located towards the center of the birds body. This is because there is no longer concentrated mass in the object.

Pirouettes

When standing, the most common place for your center of gravity to lies is in your lower abdomen. While holding your preparation, your center of gravity shifts slightly towards your lower back. Then, as you snap up into releve and raise your arms, your center of gravity shifts to in front of your body. The axis you are trying to spin around is right in the center of the circle you've created with your arms. Another very important element while performing pirouettes is torque. The amount of force required for pirouettes vary depending on factors such as friction and the position the dancer is in when beginning the pirouette. More force is required to turn in fifth position to create the same torque that would be created in fourth position. Torque can be measured by the equation T=Ia, with 'T' being the amount of "Torque", 'I' being the distance between the dancers two feet, and 'a' representing "angular acceleration". When performing pirouettes you must stay as vertical as possible. If you lean forwards or back, while turning. Then, you are throwing off your center of gravity and you are no longer spinning around the proper axis. This makes your pirouettes slower and can throw you off balance. The property "Conservation of Angular Momentum" states that "An object of constant mass will spin faster when the radius is smaller." This in more simpler terms, states that the smaller circle you make with your arms, while performing pirouettes, the faster and easier your pirouettes will become.