Unit+Seven

=Chapter Seven=

__Fluid-__

 * Fluid-a fluid is any material that can flow and that takes the shape of its container
 * Types of fluids-water, oil, oxygen, carbon dioxide, hunney, and helium
 * Fluids have a weak attraction between particles, so unlike solids, they can slosh and move around

__Atmospheric Pressure-__

 * Pressure is the amount of force on an object
 * Pressure can be calculated by pressure = Force/Area
 * You measure pressure by pascals-1pa is equal to 1n over 1 square meter
 * Fluids exert pressure evenly
 * The pressure caused by the wieght of the atmosphere is called atmospheric pressure
 * The atmosphere exerts a pressure of 101,300 pa on every square meter
 * People don't get crushed by atmospheric pressure because the fluids inside you body exerts a force on the atmosphere
 * Atmospheric pressure varies to where you are in the world- Elevation
 * Pressure depends on the depth of the fluid- the lower you are the more gravity is pulling down on the atmosphere so there is more atmospheric pressure

__Water Pressure-__
Pascals Principle
 * water pressure increases with depth
 * The deeper you go the more water pressure + Atmospheric pressure is exerted on you
 * Atmospheric pressure is less dense then water pressure so when you climb a 10 foot tree the atmospheric change is too small to notice where as if you dived 10 feet, the pressure doubles
 * When sipping from a straw the atmospheric in the straw decreases while the pressure in the cup stays the same
 * Fluids flow from regions of high pressure to low pressure-breathing is an example
 * Also happens when you open a carbonated beverage or squeeze out toothpaste
 * Pascals' Principle states that a change in pressure at any point in an enclosed fluid will be transmitted equally to all parts of the fluid.
 * An example of this is hydraulic devices. Car brakes. The driver exerts a force on the pedal, which pushes on the brake fluid which exerts pressure on all parts of the fluid. Then it pushes on the brake pads whch halts the car.

** Buoyant Force ** by Jasper Kirsten
 * CHAPTER 7 SECTION 2 **

Buoyant Force: an upward force exerted by all fluids on matter. Archimedes Principle: states that the buoyant force on an object is equal to the weight of the volume of the fluid that the object displaces. Buoyant forces are caused by differences in fluid pressure. Any object that is denser than the surrounding fluid will sink; any object that is less dense than the surrounding fluid will float. __ Weight vs. Buoyant Forces __ Sinking is caused by the weight of an object such as a rock weighs more than the buoying force so the gravity overpowers the resistant of the water thus dragging the rock to the bottom Floating is caused when an objects weight is equal to that of the buoying force so the object is essentially in the middle of a stale-mate between gravity and the buoying force. Buoying up is the term for when an objects wait is less than the buoyant force so it floats to the surface until the portion of the object that is equal to the buoyant force is in the water. __ An Object Will Float or Sink Based on It’s Density __ lf you have two pieces of steel, one that is a block and one that is shaped into a boats bottom why does the steal boat float? The block sinks because it is denser that the water but the boat floats because the form increases the volume occupied by the same mass resulting in reduced over all density so it floats.