Math & Science Period 2 (CND) Flashcards
What is another name used to indicate the hypotenuse of a triangle for calculation purposes?
Travel
What is the length relationship between the run and the offset?
The are equal
What is the length relationship between the run and the travel?
The travel is 1.414 times longer.
What two elements combine to form a water molecule?
Hydrogen and Oxygen
What does the pH scale measure?
Number of hydrogen ions.
What is the pH of neutral water?
7
What is the difference in the hydrogen ion concentration from pH4 to pH5?
10 times as strong.
What effect does acidic water have on ferrous piping materials?
Corrosion
What causes temporary hardness?
Calcium and/or Magnesium bicarbonates.
Why should a hot water tank be set at a temperature below 50*C?
To prevent temporary hardness from settling out.
What is the buoyant force available on a 5ft3 object if it is immersed in water?
Buoyant Force = 312lbs
(Buoyant force = Volume x Density of Liquid)
(Buoyant force = 5ft3 x 62.4lbs/ft3)
What is the volume of an object that weights 925kg when weighted in air, but only 570kg when weighted in water?
.355m3 (925kg-570kg=355kg/1000kg/m3=.355m3)
What will an object with a volume of 0.658ft3 and a weight of 40lb do when placed in water?
Barely float, with most of the object submerged.
Definition of flow rate?
The quantity moving in a pipe.
What is one major contributor to turbulent flow?
High velocity.
What does not affect the pressure loss in the flow of fluids in a piping system?
Static pressure in the piping system.
What is one probable cause of water hammer?
A quick closing valve.
What is the relationship between pressure and velocity in the narrowest portion of a venturi?
Pressure decreases, Velocity increases.
What causes cavitation?
Vapour bubbles forming in a low-pressure area.
What is the relationship between volume and pressure in Boyle’s law?
Pressure increases, Volume decreases.
What are the two variables in Charles’ law?
Direct relationship between temperature and volume.
A single fixed pulley is used to ?
Change the direction of force applied.
A single pulley attached to an object to be lifted?
Will increase your mechanical advantage by a factor of 2.
When multiple pulley arrangements are used to lift objects??
This arrangement will provide significant mechanical advantage.
A lever is a simple machine consisting of a rigid bar and a ?
Fulcrum.
A class three lever will always have a mechanical advantage of?
Less than 1.
A class 2 lever has a mechanical advantage of?
More than 1.
A class 1 lever has its greatest mechanical advantage if the?
Fulcrum is close to the load.
If a lever has a mechanical advantage of 3, this means that?
a 150 pound effort would move a 450 pound resistance.
The mechanical advantage of a lever assembly is a ration of the length of?
The effort arm to the resistance arm.
What type of steel should be used to manufacture wire rope slings?
Improved plow steel .
Why is a wire rope sling considered to be a complex machine with many moving parts?
The wires and strands flex, move and chafe against each other.
How is a Flemish eye for a wire rope sling prevented from coming apart?
A mechanically compressed metal sleeve is placed over the eye splice.
Why is a thimble used in a Flemish eye wire rope sling?
The thimble helps prevent premature wear of the sling’s eye.
what two main parts make up a wire rope clip?
A saddle and a U-bolt.
How is a fist grip clip different from a wire rope clip?
The fist grip clip has two identical components.
How many wire rope clips are applied to a 1” diameter wire rope to make an eye in the rope when the rule of thumb is used to calculate the number of clips needed?
Answer - 4
(The recommendation for the number of clips used to fabricate eyes on wire ropes is to multiple the diameter of the wire rope by 3, round up to the whole number and add 1.)
How is a wire rope clip applied to properly fabricate an eye in wire rope?
The U portion of the wire rope clip must be placed to grip the dead end of the wire rope.
How tight should you turn the nuts to properly attach a clip to wire rope?
Manufacturer’s torque values; after using the sling for about an hour, retorque the nuts.
Are cable laid slings stronger or weaker than comparably sized single-part wire rope slings?
Stronger.
When inspecting wire rope slings before every work shift, what areas of the sling require the most attention?
End fittings, Swaged sleeves and Hardware.
What does the term shock loading mean when applied to rigging equipment?
The sling is exposed to stress by having the load suddenly start or stop.
What are softeners for rigging?
Pads applied to sharp corners of a load.
How are sling leg angles measured?
From the angle of the sling to a line that is horizontal to the load.
What three basic hitch sling configurations are used for almost all hoisting?
Basket hitch, Vertical hitch, and Choker hitch.