Final answer:
In swimming, our limbs exert a backward force on the water, which in turn propels us forward due to Newton's third law. Swimmers also experience pressure from all sides, with a greater buoyant force from underneath due to higher pressure at deeper depths, which helps in staying afloat.
Step-by-step explanation:
When we swim, we move our arms and legs so that we push water backward. This action is based on Newton's third law, which states that for every action, there is an equal and opposite reaction. As we perform strokes and kicks, our limbs apply a force to the water in one direction, and in response, water applies an equal force in the opposite direction, propelling us forward.
Moreover, the concept of fluid pressure is also essential when understanding how swimming works. According to the physics of fluids, pressure is exerted on all sides of a swimmer. This pressure is higher at greater depths, which contributes to a net upward or buoyant force. This buoyant force helps swimmers stay afloat and is balanced by the weight of the swimmer. When moving through the water, swimmers must overcome this along with the resistance exerted by water.