Question

State the characteristics of the first-class lever. Give one example of a first-class lever where the mechanical advantage is equal to 1.

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.

Principle of a lever and expression of mechanical advantage:

1. According to the principle of moments, in the equilibrium position of the lever,

$$\begin{gathered} Momentofloadaboutthefulcrum=Momentofeffortaboutthefulcrum \\ Load\times Loadarm=Effort\times Effortarm \\ \frac{Load}{Effort}=\frac{Effortarm}{Loadarm} \\ MechanicalAdvantage\left(MA\right)=\frac{Effortarm}{Loadarm} \end{gathered}$$

2. This expression is known as the law levers.

3. The MA of a lever is equal to the ratio of the length of its effort arm to the length of its load arm.

Conditions to change Mechanical advantage:

1. $effortarm=loadarm,thenMA=1$
2. $effortarm<loadarm,thenMA<1$
3. $effortarm>loadarm,thenMA>1$
4. Thus, to increase the MA of a lever, either the effort arm should be increased or the load arm should be decreased.

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.

Characteristics of First-Class lever:

1. This is a type of lever that has the fulcrum in between the weight and the force applied.
2. Its order is represented as force-fulcrum-weight.
3. This is the most basic type of lever.

Example of first-class lever:

1. Our hand pushing an object or seesaws, crowbars.
2. Using scissors represents the use of two first-class levers.
3. A wheel and axle is also an example.
4. Pulling a nail out of a wooden plank also represents a first-class lever.

One example of a first-class lever where the mechanical advantage is equal to 1:

1. A first-class lever has the fulcrum in the middle and the load and effort on each side of the fulcrum.
2. Its mechanical advantage is equal to 1.
3. A seesaw is an example of a first-class lever because the fulcrum lies between the effort and the load.

the

Hence, the see-saw is an example of a first-class lever having a mechanical advantage equal to one.