150+ QUESTIONS WITH ACCURATE ANSWERS
What is a lever?
Accurate Answer: A machine consisting of a beam or rigid rod pivoted at a fixed hinge or
fulcrum
How do levers work?
Accurate Answer: Amplifies an input force to provide a greater output force, which is said to
provide leverage
What is the mechanical advantage of a lever?
Accurate Answer: The ratio or the output force to the input force
How are levers classified?
Accurate Answer: By relative positions of the fulcrum and the input and output forces.
Allows identification by the relative locations of the fulcrum, the resistance, and the effort.
Class 1 Lever
Accurate Answer: Fulcrum in the middle
The effort is applied on one side of the fulcrum and the resistance on the other side.
Examples of Class 1 levers:
,Accurate Answer: See saw, crowbar, scissors
What is the mechanical advantage of a Class 1 lever?
Accurate Answer: It may be greater than or less than 1
Class 2 Lever
Accurate Answer: Resistance in the middle.
Effort is applied on one side of the resistance and the fulcrum is located on the other side.
Examples of Class 2 levers:
Accurate Answer: Wheel barrow, a nutcracker, a bottle opener or the brake pedal of a car
What is the mechanical advantage of a Class 2 lever?
Accurate Answer: It is always greater than 1
Class 3 Lever
Accurate Answer: Effort in the middle
The resistance is on one side of the effort and the fulcrum is located on the other side.
Examples of Class 3 levers
Accurate Answer: Tweezers or the human mandible
Mechanical advantage is always less than 1
, FRE 123
• Fulcrum in middle for 1st class
• Resistance is in the middle for the 2nd lever
• Effort is in the middle for the 3rd
A belt and pulley system is characterized by
Accurate Answer: Two or more pulleys in common to a belt.
What does a belt and pulley system allow for?
Accurate Answer: Mechanical power, torque, and speed to be transmitted across axles
How is mechanical advantage realized?
Accurate Answer: If the pulleys are different diameters
What is a pulley?
Accurate Answer: A wheel on an axle or shaft that is designed to support movement and
change of direction of a cable or belt along its circumference
Why are pulleys used?
Accurate Answer: Lift loads, Apply forces, Transmit power