Mechanical Fundamentals Flashcards
Like atoms that bond together chemically from molecules of a…
Element
Unlike atoms that are chemically bound together form molecules of a…
Compound
Water is a ___ with two kinds of atoms, hydrogen and oxygen.
Compound
What is it called when two things are mixed together and don’t chemically combine?
Mixture
What is the state of matter determined by?
Temperature and pressure
As molecules are heated…
Speed increases and volume expands
What is it called when there’s no lower temperature than when molecules cease motion?
Absolute zero
Vacuum is a…
Closed space which all air and gases are removed
Resistance of fluid flow varies with types of ___ and ___.
Fluids and temperatures
Viscosity is…
Resistance to change in a liquid flow and shape
What are the two kinds of energy?
Potential (position of mass) and kinetic (motion of mass)
What are the two kinds of velocity?
Constant and variable
Velocity is the …
Rate a mass travels in a direction
Water hammer is…
Force/ shock when a liquid and a confined space is suddenly accelerated
What are 6 simple machines?
Levers, wedge, inclined plane, pulleys, wheel and axle, screws
Third class levers multiply ___ and ___ instead of force.
Speed and distance
If the wheel is driving the axle, there is a loss in _______ because the driving belt is going seven times faster and further distance.
Mechanical advantage of speed
On simple machines it is impossible to gain ___ and ___ at the same time.
Force and speed
The four purposes of gears.
- Transmit positive motion
- To drive a second part in same or different direction of motor/ driving force
- To actuate second gear at the same speed or different than the driver
- To increase or decrease force
With an odd number of gears in a simple gear train the driver and driven gears rotate and the ___ direction.
Same
On an inclined plane what is the effort distance?
The length of the slope
What are the four purposes of screw threads?
- To transmit motion
- To apply tremendous forces with little effort
- To hold parts together
- To obtain measurements
Most screw threads are said to have…
A definite number of threads per inch
Work definition
Overcoming resistance
Turbulance
Loss of head at entrance of pipe
Flow rate
Quantity of substance that moves past a point in a given time
Pressure definition
Force exerted by a substance on a unit of area
Energy definition
Capacity to do work
Gravity definition
Acts in accordance with the law of falling bodies
Power definition
Rate at which work is done
Acceleration definition
Rate at which velocity increases with time
Friction definition
Force that resists relative motion of 2 bodies that are in contact with each other
