Question

You feel lighter when you swim. Give reasons.

Answer 1

Hint: Recall the concept of Archimedes principle. This principle is used here. According to this principle, the upward buoyant force acting on a body fully or partially immersed in fluid, is equal to the weight of the fluid that the body displaces.

Complete answer:
As we swim, we feel lighter or little weightless. This is because our body is immersed in water whether fully or partially. As per Archimedes principle, the water exerts an upward force or buoyant force on our body. This is because the weight of our body in water is equal to the apparent weight.
The pressure increases with increase in depth. So at the bottom of the fluid, the body will experience more pressure. So the pressure will be different at the top and the bottom of the fluid. This difference in pressure results in an upward force. The water exerts this force in an upward direction. As a result, the weight of our body reduces. Thus we feel lighter when we are in a swimming pool due to the buoyant force.

Note: It is important to remember that the buoyant force and the upthrust are the same forces. Buoyant force is the force that makes an object or a body floats. It is caused by the difference in the pressure acting on the opposite sides of the body immersed in the fluid. If the density of the body is greater than the density of the fluid in which it is submerged, then it will sink. If the density of the body is less than the fluid, then it will float.