Navika Chowdhary_10B_Physics Project_STORYBOARD
Kuvakäsikirjoitus Teksti
- Hmmm..
- MOM, what is the physics behind swimming?
- Swimming is a popular activity, both for recreation and competition. The physics of swimming involves an interaction of forces between the water and the swimmer. It is these forces which propel a swimmer through the water.
- Okay so what are the forces acting on a floating body?
- In order to float in water an object must be less dense than the water. This difference in density causes the object to float. This happens by way of a buoyancy force that "lifts" the object.
- The principle behind this lift is called Archimedes' principle, which states that any object (regardless of its shape) that is suspended in a fluid (such as water), is acted upon by an upward buoyant force equal to the weight of the fluid that is displaced by the object.
- This weight is equal to the buoyant force pushing upward on the object. The amount that the object sinks below the water surface corresponds to the equilibrium point, in which the object weight is equal to the buoyant force pushing upwards on the object.
- When an object is placed in a fluid such as water, and floats as a result, the part of the object that lies below the surface of the water displaces a water weight equal to the weight of the object.
- Furthermore, the buoyant force acts through the center of buoyancy, which is the centroid (center) of the immersed part of the object - this is the volume of water that is displaced by the object. For the object to maintain its orientation in the water (i.e. not rotate) this buoyant force must pass through the center of mass of the object.
- If this buoyant force does not pass through the center of mass, and is offset from it as shown in the figure below [1], then the object will rotate until the buoyant force passes through the center of mass. At this point rotational equilibrium is reached. In the figure below the buoyant force acts at a point that is to the right of the center of mass and as a result will cause the swimmer to rotate counterclockwise.
- Thankyou so much mom!
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