L4: Physics of Fluids

Fluid Mechanics

is the branch of physics that studies the behavior of fluids and thee forces acting on them.

Density

defined as the radio of the mass of the fluid to its volume. It describes how much mass is packed into a given volume.

Specific weight

defined as the weight possessed by the unit of a fluid.

Temperature

it measures the average kinetic energy of liquid’s molecules.

Pressure

describes the force exerted by the liquid per unit area, it is the way the fluid pushes against things around it.

Surface tension

describes the tightness of the liquid’s surface that is caused by the attraction between its molecules that act like an invisible skin on the surface of the liquid. It is the force that makes the surface of a liquid act like stretched skin.

Archimedes principle

states that any object that is completely or partially submerged in a fluid experience an upward force equal in magnitude to the weight of the fluid displaced by the object.

Pascals principles

states that the external static pressure applied on a confined liquid is distributed or transmitted evenly throughout the liquid in all directions.

Hydraulic lift

consist of two pistons filled with oil/water with their reservoirs connected by a tube. If we increase the force on the smaller piston, the force acting over the area of piston increases the pressure in its reservoirs. The change in pressure is transmitted through the oil into the larger piston.

Hydraulic breaks

is an arrangement of the braking mechanism in which brake fluid is used to transfer pressure from the control mechanism to the brake mechanism. When we apply a little force on the pedal, the master piston moves inside the master cylinder, and the pressure is transmitted through the brake oil to act on a piston of larger area.

Hydraulic press

is an arrangement of the braking mechanism in which brake fluid is used to transfer pressure from the control mechanism to the brake mechanism. When we apply a little force on the pedal, the master piston moves inside the master cylinder, and the pressure is transmitted through the brake oil to act on a piston of larger area.