Question

State the characteristics of class II lever and give two examples.

Answer 1

Levers:

1. It is the simplest and most common machine used in everyday life.
2. A lever is a rigid, straight or bent bar capable of rotating around a fixed point or its axis called the fulcrum.
3. A fulcrum (F) does not move but remains fixed when a lever is in use.

Classification of levers:

1. According to where the load and effort are located with respect to the fulcrum, there are three types or classes of lever: First-Class Lever, Second Class Lever, and Third Class Lever.

Second Class Lever:

1. In this, the fulcrum is at one end and the force applied is on the other end.
2. The load is situated in the middle of these two.
3. The order of this would be fulcrum-load-force.
4. The application of force at one end will result in some work done on the other end.
5. The load and effort are in opposite direction.
6. The effort arm is always longer than the load arm.
7. The mechanical advantage (MA) and velocity ratio (VR) are always greater than 1.
8. It acts as a force multiplier.

Example of second class lever:

1. Wheelbarrow
2. Staplers
3. Doors or gates
4. Bottle openers
5. Nutcracker
6. Nail clippers