Presentation on theme: "Transmitting Pressure in a fluid. 11-2 Pascals Principle In 1600 a French mathematician stated that “When force is applied to a confined fluid an increase."— Presentation transcript:
Pascals Principle In 1600 a French mathematician stated that “When force is applied to a confined fluid an increase in pressure is transmitted equally to all parts of that fluid”. This is known as Pascal’s Principle.
A force pump causes the fluid to move from one place to another by increasing the pressure in the fluid.
Force Pumps For example: tube of toothpaste, ketchup bottle, your heart
Using Pascal’s Principle Page 356 for graphic. What does the graphic show? That when you increase the area of the piston you are multiplying the force.
Buoyancy Buoyant forces act on submerged objects. The buoyant force acts in the upward direction, against the force of gravity, so it makes the object feel lighter.
Buoyancy Fluid pressure is exerted in all directions on a submerged object. Since pressure increases with depth, the upward pressure is on the bottom of an object is greater than the downward pressure on the top. The net force acts upward and is called buoyant force.
Archimedes Principle The buoyant force on an object is equal to the weight of the fluid displaced by the object.
Sinking If the weight of the object is greater than the buoyant force the object sinks. It only sinks far enough to displace a volume of liquid =to its own weight
Density Density is mass/volume. An object that is more dense than the fluid in which it is immersed sinks. An object that is less dense than the fluid in which it is immersed floats. Density of water = 1.0 g/mL
Floating If the weight of the object is less than the buoyant force,
Applying Bernoulli’s Principle Figure 7.3: Lift of an aircraft wing
Bernoulli’s Principle The pressure exerted by a moving stream of fluid is less than the pressure of the surrounding fluid. PIRA 2C20.30 Bernoulli's Principle: Floating Tetherball.
Objects in flight Apply Bernoulli’s Principle by their shapes. Different shapes cause the air to move at different speeds above and below them.
Airplane wings? They are shaped so that the air moves faster over the top of the wing and pressure pushes the object upward.