A Brief Note on Moment of Force

Have you ever witnessed the spinning wheels generating power? Or saw the car engines spinning to produce energy? All such phenomena in physics are defined as moment of a force. Force is a crucial part of any movement that physics explains. Be it the push and pull effect or the rotational axis. Force plays a major role in it. One such part of the force is the moment of force formula. There are various practical moment of force examples that we witness in our daily routines. But the catch is, we never realise it as it continues happening. 

Understanding the moment of force would first require interpreting force rightly. In the below information, there will be an elaboration on what force is. There will also be elucidation on the moment of force formula and types of moment of force. Further, there will be the moment of force examples to facilitate better understanding of the concept and the significance of moment of force. 

What is Force According to Physics?

In simple sense, force is synonymous to push and pull between two objects that come in contact with each other. If two objects interact or collide with each other, they are said to be exerting force on each other. Force can only persist when two objects come in contact. Without any contact, there is no force present. 

Forces can be contact forces or forces consequent to actions at a distance. When there is a physical interaction between two or more objects, the force exerted is known as contact forces. In contrast, when two objects are not in physical contact, the force present is force consequent to actions at a distance. Here, the force that is present is the gravitational force. 

Under the contact forces, there are several other kinds of forces classified in the same category. These are frictional force, normal force, applied force, air resistance force, etc. Under the forces consequent to actions at a distance, there are classifications too. These are magnetic force, electric force and gravitational force. 

Force is measured in a standard unit known as Newton. It is a vector quantity which indicates that it has both direction and magnitude. This means that force can move towards a particular direction or directions. It can range between lower, average and high magnitude, depending on how it has been exerted. 

Force is represented through vector diagrams which indicate the direction and magnitude through arrows drawn. Under force, there is a whole new concept of moment of force. The following section has a detailed elucidation on it. 

What is the Moment of Force?

Moment of force is defined to be the turning ability of force. It is a force that rotates the body or the object on a particular axis, end or point. This moment of force is also known as torque, rotational force or the turning effect. However, it varies based on the two fields, physics and mechanics. 

Moment of force measures the tendency that rotates the body at a definite point. However, this tendency is highly different from the tendency that moves an object. Here, the force should begin in a pattern that starts rotating the object. The moment of force will occur when there is an absence of equal and opposite force along the object’s direction. 

Example

If you and your friend are pushing a door from both ends, it will create force but not moment of force. As long as you both are pushing, it will be classified as an equal force. However, once you opt out of pushing, your friend is the only force exerting party. As you leave from exerting any force, the door would twist and swing open. Here, the twist of the door’s swing openness is the moment of force. 

Moment of force formula indicates that it is directly proportional to the distance of the point. Here the distance of the force is from the focal axis or point. Moment of force formula is the product of the force and moment arm. Force is represented as F, and moment arm is represented as d. Moment arm is the measured perpendicular distance between the action line of force and centre or its axis. 

Mathematically, the moment of force formula can be represented as,

Moment= Force x Moment Arm,

Which is

M= (F)(d)

Here, 

M= Moment of force

F= Force line

d= Moment arm

Further, the moment of force is expressed as Newton metre, foot-pounds, kip feet and kilonewton metres. There are various moment of force examples. These are the rotation of the doorknob, the movement of the spanner turning a nut and movement of the seesaw.  

Apart from these, there are various types of moment of force. These are:

• Clockwise Moment of Force

• Anticlockwise Moment of Force

There are various signs of the moment of force. These are elaborated on in detail in the next section.

Significance of Moment of Force

The moment of force plays an essential role in various applications. These are as follows:

• Moment of force is used to calculate an object’s mass as the force is exerted in a circular motion.

• Moment of force formula is used by civil engineers to understand how much the bedding will take place when the force is exerted by the equipment.

• Moment of force essentially implies the role of rotational force. In cases where there is no equal or opposite force, the rotational force might be acting.

• Moment of force is used in levers or simple machines.

• Apart from this, moments of force can be witnessed across various day to day objects, such as the kettle rim, bicycles and spanners for repair.

These are the pointers that indicate the significance of moment of force. Moment of force formula gives the amount of rotational force exerted on an object. It is explainable through the practical moment of force examples. 

Conclusion

The above information discusses the topic of force. One integral part of the force is the moment of force. The moment of force is indicative of the force that is exerted on the rotating body. The information above also includes the moment of force formula used for calculation.

There is also mention of the types of moment of force and practical moment of force examples.