CORRECT DETAILED ANSWERS WITH RATIONALES (VERIFIED
ANSWERS) |ALREADY GRADED A
Classes of Levers - ANSWER: Class 1,
Class 2,
Class 3
Class 1 Levers - ANSWER: Fulcrum is in the middle, with the effort (input) force on
one side of the fulcrum and resistance (output) on the other side
.Mechanical Advantage greater or less than 1
Ex: Seesaw, Crowbar, Pair of Scissors.
Class 2 Levers - ANSWER: Resistance is in the middle, the effort is applied on one
side of the resistance and the fulcrum on the other side
.Mechanical Advantage is always greater than 1
Ex: Wheelbarrow, nutcracker, bottle opener, or the brake pedal of a car.
Class 3 Levers - ANSWER: Effort in the middle, the resistance is on one side of the
effort and the fulcrum is located on the other side.
Mechanical Advantage is always less than 1
Ex: Pair of tweezers, human mandible
Lever Definitions - ANSWER: Lever machine consisting of a beam or rigid rod
pivoted at a fixed hinged, or fulcrum.
Input Force = Effort
Output Force = Load or Resistance
What does "fre, 123" mean? - ANSWER: Fulcrum is in the middle for Class 1
LeversResistance (output) in middle for Class 2Effort (input) in the middle for Class
3
Formula for Determining the head pressure difference between an intake and output
- ANSWER: 1 vertical foot = 0.433 psi
1 psi = 2.31 vertical feet
Overall Test Overview: - ANSWER: 1) 30-minute period to read 2 essays- 2-hour
time limit begins to answer (100 questions).
2) Watch 2 short videos and answer (20 questions) based on the scenarios.
3) Apply mechanical reasoning (25 questions, i.e. Fluid Dynamics, levers, belt and
pulleys, gears)
4) Mathematical Problems (20 questions, i.e. addition, division, angles, area,
volume, decimals, ratios, percentages)
5) Recall and Comprehend Technical Information (35 questions, recall from first
two essays, in addition to one or two more at this time)
, Be mindful of questions with absolutes. What are some absolutes and why watch
out for them? - ANSWER: Examples of absolutes are "absolutely, always, forever,
completely, infinite, never, only, sole, undeniable, or wholly".Absolutes or any sort
of broad statements should be suspected as wrong.
Recall and Comprehend Technical Information - ANSWER: - Read one to four essays
-35 questions total (including questions for essays in back of the test booklet)
- notes can be written on the essay packet, NOT any other testing material.
- 15 - 20 questions from these essays were handed out in the first 30 minutes.
Gear Train, or commonly called "Transmission" - ANSWER: Two or more gears
working in a sequence, producing mechanical advantage through a gear ratio.
Relationship between Speed, Torque, and Power: - ANSWER: Power = 2pi x Speed
(w) x Torque (nm)/ 60
Torque = 60 x Power (kW)/2pi x Speed (Rpm)
Belt and Pulley Systems - ANSWER: Two or more pulleys in common to a belt. If the
pulleys are of differing pitch diameters, a mechanical advantage is realized.
Doesn't depend on ratio of teeth as with gears and sprockets, only pitch diameter.
What is a pulley (also called a "sheave" or "drum") - ANSWER: A pulley is a wheel on
an axle or shaft that is designed to support movement and change in direction of a
belt or cable along its circumference.
For a Rope and Pulley System that is a Block and Tackle, is characterized by: -
ANSWER: * If the rope does not dissipate or store energy, then its mechanical
advantage is the number of parts of the rope that act on the load.-
if the anchor knot is at the load ("A", "D", and "E") then the mechanical advantage
will be odd. (1:1, 3:1, 5:1, etc.)-
if the anchor knot is at the anchor ("B", "C") then the mechanical advantage will be
even. (2:1, 4:1, 6:1, etc.)-
to calculate haul distance, multiply the distance need to go by the mechanical
advantage. (3:1 ratio, 20 ft to haul, multiply 3 x 20 ft to get a total of 60ft)
How much water can be held in engine 17 water tank - ANSWER: 105 feet Sq
How many gallons with a tank of 12 ft diameter hold if it is 5 feet deep - ANSWER:
4320
Engine carries lots of hose. 4" was removed - ANSWER: 30% left
How many acres were burned - ANSWER: 6.88 acres