| |
|
|
| |
 |
| Introduction |
|
| Fluids |
| |
| Fluids are substances which begin to flow when external force is applied on them. Liquids and gases are fluids. Fluids do not have a definite shape. The branch of physics, dealing with the study of fluids at rest is called hydrostatics. |
| |
| When fluids are kept in a container, due to random motion of the molecules (intermolecular forces are less) they constantly collide with the wall of the container and rebound from them. Due to this, they suffer change in momentum and this momentum, transferred to walls per unit time, accounts for the force or thrust on the walls of the container. |
| |
| Forces acting on a fluid in equilibrium of rest, are always perpendicular to its surface. This can be seen as follows: |
| |
 |
| |
| Consider a force acting along AB. In reaction, a force is executed along BA. On resolving the forces, Fcosq along the horizontal direction, tends to move the liquid as the liquid surface cannot resist the tangential force Fcosq. But since the liquid is at rest, no component of force acts along the horizontal. Therefore, the liquid at rest, exerts a force at B or any point perpendicular to surface of the container. |
| |
|
|
| |
|
|
| |
|
|
|
