Simple Definition of Centre of Gravity

The position of the center of gravity of a body can coincide with the geometric center of the body, especially in an object of symmetrical shape made of a homogeneous material. However, an asymmetric object composed of a variety of materials of different masses is likely to have a center of gravity located at some distance from its geometric center. In some cases, such as hollow bodies or irregularly shaped objects, the center of gravity (or center of mass) in space can occur at a point outside the physical material, such as in the center of a tennis ball or between the legs of a chair. The center of gravity of any body can also be determined by a simple physical procedure. For example, for the plate in the figure, the G-spot can be located by hooking the plate to a string attached to point A, and then to a string attached to C. If the plate is suspended at A, the AD line is vertical; if suspended on C, the EC line is vertical. The focus is on the intersection of AD and EC. When an object is suspended at a single point, its center of gravity is directly below that point. Image: The center of gravity of a crane rises when lifting its load and can make it unstable if the load tilts too far to the side. The arrows widen the base to prevent tipping. Photo by Werner Slocum courtesy of NREL (National Renewable Energy Laboratory) (Photo ID #144647). In physics, imaginary point in a body of matter where, to simplify, the total weight of the body can be considered concentrated in certain calculations. The concept is sometimes useful for working with static structures (e.g., Buildings and Bridges) or predicting the behavior of a moving body when affected by gravity.

Subscribe to America`s largest dictionary and get thousands of other definitions and an advanced search – ad-free! If you`re ever in a rowboat, understanding the center of gravity will help you stay safe and dry. Hop on a small boat and you suddenly have a much higher center of gravity that can easily knock you over if the boat turns and capsizes (overturns) under you. Stay low and you`ll find it easier to stay balanced. Large boats have vertical wooden “fins” called keels at their bottom, partly to prevent them from capsizing, partly to help them navigate more efficiently when the wind blows them sideways. Artwork: How to find the center of gravity of an object: 1) Hang the object at a point on its edge and it rotates until its center of gravity is just below that point. Hang a plumb line (a weight on a string) in the same place. Draw a line parallel to the chain (yellow). 2) Now select another point on the edge and repeat the process. Draw another line parallel to the string (green). 3) The center of gravity of the object is the point where the two lines meet. There is another way to think about your weight.

Yes, your body is a bit like a sack of potatoes. But it`s also a bit like a giant potato that weighs as much as you do, focusing on an infinitely small point, somewhere in the center — pretty much where your stomach is. This is your personal goal. As long as your center of gravity is more or less above your feet, your body will always be balanced and you will not tip over. But lean to the side, and everything changes. Your head is one of the heaviest parts of your body – like a giant potato sitting just above it. When you lean to the left, your center of gravity is no longer directly above the center of your feet. The more you bend over, the more torque it creates and the more likely you are to tip over. Gravity makes your whole body rotate around your ankles like a finger pressing on a doorknob.

The point of each solid where a single applied force could support it; Point at which the mass of the object is uniformly balanced. The center of gravity is also called the center of gravity. When a man leans so far to the side of a ladder that his center of gravity is no longer above his feet, he begins to fall. In a uniform gravitational field, the center of gravity is identical to the center of mass, a term preferred by physicists. However, the two do not always coincide. For example, the center of mass of the moon is very close to its geometric center (this is not exact because the moon is not a perfect uniform sphere), but its center of gravity is slightly shifted towards the Earth due to the stronger gravitational force on the side near the moon. Photo: Low center of gravity: The high jump technique shown here, called Fosbury Flop, works by keeping the center of gravity low enough to go under the bar. Photo by Matthew L.

Romano courtesy of the US Navy and Wikimedia Commons. Photo: Shipmasters, aircraft and aircraft pilots and crane operators must consider the impact of cargo on the vehicles they operate. Here, the center of gravity of a helicopter with a side load shifts to the left when we look at the image. The pilot must adjust the pitch of the rotors so that they generate more downforce on the left to compensate for this. Photographer unknown. Photo courtesy of the National Archives. Tightrope walkers use a slightly different trick to control their center of gravity. If you`ve ever watched a tightrope walker, you`ll have noticed that it never walks on the rope. Some stretch out their arms or carry a long stick or umbrella. Others squat or bend their knees.

Still others ride bikes with weights that hang slightly under them. These balancing aids help give tightrope walkers more control over their center of gravity. If they can always keep their center of gravity directly above the rope, they will never fall. When they begin to move to the side, a rotational force will begin to plunge them in that direction. They must therefore quickly move a part of their body to the other side to create a rotational force in the opposite direction and restore their balance. Photo: Why is focus important? If you want to fly an aircraft safely, a balanced load is important. 1) This huge C-5 aircraft calculated its center of gravity in a special weight and balance hangar at Edwards Air Force Base in California. Photo by Derek Lawrence courtesy of the National Archives. The deeper your center of gravity, the easier it is to keep your balance. Sitting in a chair allows you to bend over more than when you stand up. If your center of gravity is low, you can lean further to one side or the other without creating enough torque to tip you over. That`s why racing cars (and military vehicles like the Humvees) are designed with very low centers of gravity: the lower they are on the ground, the lower the risk of them tipping over, regardless of their speed.

“Focus.” Merriam-Webster.com Dictionary, Merriam-Webster, www.merriam-webster.com/dictionary/center%20of%20gravity. Retrieved 8 October 2022. If you need to balance something and you can`t lower the center of gravity, another option is to expand the base. When standing on the deck of a ship in rough seas, it`s easier to keep your balance if you spread your feet farther, expanding your own base. Even if your body tilts to the side, your center of gravity is still in the area of your base and you should be able to stand. You can see the same idea when working in cranes. If you have a very tall crane that lifts a heavy load, it can use side-elongated legs called booms to keep it stable. Photo: Bears sometimes walk on their hind legs, but it`s faster, easier and safer to crawl – because they have a lower center of gravity and can`t tip over.

Image by Erich Regehr courtesy of US Fish & Wildlife Service. Photo: 1: The U.S. Army`s Humvee (High Mobility Multipurpose Wheeled Vehicle, HMMWV) has a low center of gravity, allowing it to drive through high-speed corners on difficult terrain, with much less risk of overturning. 2: Nevertheless, soldiers are trained to escape from an overturned lobster using this hydraulic simulator called HEAT (HMMWV Egress Assistance Trainer). It runs a model of the Hummer`s cockpit, allowing soldiers to practice landing in a variety of harsh conditions, including underwater. Photo of the Hummer by Sergeant Alex Snyder, HEAT photo by Sergeant Travis Zielinski, both courtesy of the U.S. Army. Photo: It`s easy to fall off a regular bike where your weight balances on a very thin wheel and even slight movements from side to side can tip you over. It`s almost impossible to fall off a recumbent bike (a bike like this where you sit) because the center of gravity is almost at ground level.

Photo by Charles M. Bailey courtesy of the U.S. Army. Artwork: As long as your center of gravity (yellow star) remains approximately above the center between your feet, you will remain standing even during complex movements like walking and dancing.