Torque is the measure of the force that can make an object to rotate about an axis. It is rotational equivalent of linear forces. It is the measurement of the turning force of an object.
It is produced by coupling forces. For example; a rotational force that works on the ceiling fan causing it to rotate about its axis which is due to the magnetic effect of the current is Torque or the force that causes a bolt to come out when rotated with a wrench, it is Torque and there are various daily life examples where you can observe Torque.
On the other hand, Moment in terms of physics is the measure of the tendency of a force that can cause a body to rotate about its axis. A moment is due to a force not having an equal and opposite force directly along its line of action. Moment unlike Torque is static in nature, for example; if two intelligent boys pushing a door along each other’s line of action but in the opposite direction of each other and one decides to back off then the person who was still pushing on the door created a moment.
The moment is static in nature and is only available only for a moment but Torque is both static and dynamic in nature and Torque is something that produces angular acceleration but in a case of the moment there is no angular acceleration due to this.
Torque vs Moment
The main difference between Moment and Torque is that Moment is static in nature while Torque is dynamic in nature. Torque can produce angular acceleration or de-acceleration but Moment is not capable of doing such thing as it is a force of static nature which is only for a moment of time and if this changes the direction of motion that it is not Moment.
They both are directly proportional to the distance from the axis of rotation of the body. A simple way to calculate Torque is to multiply the applied force with the lever arm. Moment and Torque are perpendicular to the line joining the hinge and the point of application of force. They both have different SI units Torque has SI unit N-m/revolution whereas the SI unit of Moment is NM.
They both also have different symbols while Torque is represented as a Greek letter in lowercase Tau whereas Moment is represented as M which can be seen in its SI unit. Moments are of different kinds such as the moment of force, a moment of momentum, etc.
Comparison Table Between Torque and Moment?
| Parameter of Comparison | Torque | Moment |
|---|---|---|
| Definition | Measurement of a force that causes rotation of a body | Measurement of tendency of a body to cause its rotation |
| Symbol | Greek lowercase letter tau | M |
| SI unit | N-m/revolution | NM |
| Availability | It used where there is rotation | It used essentially in non-rotational events |
What is Torque?
Torque is the measure of the force that can make an object to rotate about an axis. It is the rotational equivalent of linear forces. It is the measurement of the turning force of an object. It is produced by coupling forces. For example; a rotational force that works on the ceiling fan causing it to rotate about its axis which is due to the magnetic effect of the current is Torque or the force that causes a bolt to come out when rotated with a wrench, it is Torque and there are various daily life examples where you can observe Torque.
Torque has SI unit N-m/revolution and it is represented as Greek letter in lowercase Tau. Torque is both static and dynamic in nature and Torque is something that produces angular acceleration but in the case of a moment, there is no angular acceleration due to this.
What is Moment?
A moment in terms of physics is the measure of the tendency of a force that can cause a body to rotate about its axis. A moment is due to a force not having an equal and opposite force directly along its line of action.
Moment unlike Torque is static in nature, for example; if two intelligent boys pushing a door along each other’s line of action but in the opposite direction of each other and one decides to back off then the person who was still pushing on the door created a moment.
The moment is static in nature and is only available only for a moment and it unlike Torque cannot produce angular acceleration at it is just a momentary force. The SI unit of Moment is NM and is represented as M.
Main Differences Between Torque and Moment
- The measurement of a force that causes rotation of a body is Torque whereas the Measurement of the tendency of a body to cause its rotation is Moment.
- The symbol for Torque is tau whereas for Moment is MSI unit of Torque is N-m/revs and of Moment is NM
- Torque is used where there are coupling forces of rotating in nature and Moment is used where there is no rotating force situation.
- Torque is a force of dynamic and static nature whereas Moment is a force of static nature.
- It is to this static nature Moment cannot produce angular acceleration like the Torque.
Conclusion
They both are analogous of force but the Measurement of a force that causes rotation of a body is Torque whereas the Measurement of the tendency of a body to cause its rotation is Moment. Torque is a force of dynamic and static nature whereas Moment is a force of static nature.
They both have different SI units Torque has SI unit N-m/revolution whereas the SI unit of Moment is NM. They both also have different symbols while Torque is represented as a Greek letter in lowercase Tau whereas Moment is represented as M which can be seen in its SI unit.
References
- https://ieeexplore.ieee.org/abstract/document/8464304/
- https://asmedigitalcollection.asme.org/manufacturingscience/article-abstract/99/3/715/428392