The center of mass of an irregular object is the point where the entire mass of the object can be considered to be concentrated. It is the average position of the mass of the object.
The CM of an irregular object can be calculated by dividing the object into smaller, simpler shapes and finding the CM of each shape. Then, the overall CM is determined by taking the weighted average of these individual CMs, where the weights are the masses of each shape.
The CM is important in physics because it is used to describe the motion of an object. The motion of an object can be described as if all the mass of the object is concentrated at the CM, making calculations simpler.
Yes, the CM of an irregular object can be outside of the object. This is possible when the distribution of mass within the object is not symmetrical, causing the CM to be displaced from the object's physical center.
The shape of an object can affect its CM because it determines the distribution of mass within the object. Objects with symmetrical shapes will have their CM at the center, while objects with irregular or asymmetrical shapes will have their CM at a different location.