Test Flashcards
Element for Gold
Symbol-Au
Atomic weight- 197
Specific gravity- 19.32@17.5 C
Elements are-
When like atoms bond together chemically, they form a molecules of an element.
Compounds-
A compound is any substance whose molecules are composed of unlike atoms.
Water is a compound because the molecules are composed of two kinds of atoms, hydrogen and oxygen.
Mixtures
When two different elements or compounds are mixed together and the molecules do not combine chemically, the substance is known as a mixture.
States of matter
Is determined by two things, it’s temperature and it’s pressure
Molecules of solids
As they are heated, their activity or molecules speed is increased
Absolute Zero
When a substance gets so cold that it’s molecules would cease to move, it could not get any colder.
Two kinds of energy
Potential energy- that due to the position of a mass
Kinetic energy- that due the motion of a mass
The rate at which work is done is called
Power
There are two kinds of velocity
Constant and veriable
The force or shock which results when the movement of a confines liquid is suddenly arrested or accelerated.
Water hammer
The Six Simple Machines
Lever Inclined plane Wedge Screw Wheel and axle Pulley
Levers of the third class
Multiply speed or distance, rather than force.
If the wheel is driving the axle, there is a loss in mechanical advantage of speed because
The driving belt is traveling faster and farther than the driven belt on the axle
On a simple machine
It is impossible to gain both force and speed at the same time.
Gears serve four-fold purpose:
(1) gears transmit positive motion
(2) gears are used to drive a second part or mechanism in the same or opposite direction to that of the motor or other driving force; (3) gears are used to actuate a second gear or part at the same speed, slower or fastest than driver; (4) gears may be used to increase or decrease force
With a odd number of gears in a simple gear train.
The driver and the driver gears rotate in the same direction.
The length of the slope
Is the effort distance (ED)
Screw threads are used
(1) to transmit motion
(2) to apply tremendous force with comparatively little effort
(3) to hold parts together
(4) to obtain measurements
Most screw threads are said
to have a definite number of threads per inch.
Rate a mass travels in a particular second
Velocity
A force that resists motion of tendency to such motion of 2 bodies of substances at contact.
Friction
Loss of head pressure at entrance of a pipe
Turbulence
Closed space which all air is removed
Vacuum
Resistance to flow
Viscosity
Force exerted by substance on a unit of area
Pressure
The quantity of a substance that moves past a point in a given length of time
Flow rate
Force of one body onto the other with exert the same of resistance
Inertia
Closed conduit to move water from a pump
Penstock
Storage of liquid above the plant
Forebay
Rate at which velocity of a mass increases with time
Acceleration
Density
At of unit per volume
Is a comparison of the density of any substance with the density of water
Specific Gravity
What tends to change velocity of a mass
Force
