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 re-
sistance (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 ful-
crum on the other side.
Mechanical Advantage 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 always less than 1
Ex: Pair of tweezers, human mandible
1
, 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 Levers
Resistance (output) in middle for Class 2
Effort (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, deci-
mals, ratios, percentages)
2
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 re-
sistance (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 ful-
crum on the other side.
Mechanical Advantage 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 always less than 1
Ex: Pair of tweezers, human mandible
1
, 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 Levers
Resistance (output) in middle for Class 2
Effort (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, deci-
mals, ratios, percentages)
2
