Moment of force. Force and distance

What is the moment of force, what effects does it produce and how are the moments balanced?

Online moment of force simulations will allow you to study how moments act on objects in different situations and how equilibrium can be achieved with different combinations of force and distance.

The moment of force, also known as moment or torque, is a physical quantity that describes the tendency of a force to cause a rotation around a specific point or axis. It is produced by the application of a force at a given distance from the point of rotation.

The moment of force is calculated by multiplying the magnitude of the force by the perpendicular distance from the point of rotation to the line of action of the force. Mathematically, it is expressed as:

Moment = force × distance × sin(θ).

Where:

Force is the magnitude of the applied force.

Distance is the perpendicular distance from the point of rotation to the line of action of the force.

θ is the angle between the direction of the force and the line joining the point of rotation to the point of application of the force.

The moment of force is measured in a unit called newton-meter (Nm) in the International System (SI).

The moment of force can be positive or negative, depending on the direction of rotation it induces. If the moment is positive, it indicates a clockwise rotation, while if it is negative, it indicates a counterclockwise rotation.

The moment of force is fundamental in the study of statics and dynamics of objects in equilibrium or in motion. In statics, the moment of force is used to analyze the equilibrium of an object, where the sum of the moments of all the forces must be equal to zero so that there is no tendency to rotate. In dynamics, the moment of force is related to the angular acceleration and rotational inertia of an object.

The moment of force has numerous practical applications in fields such as engineering, mechanics, architecture and physics, where they are used for the design of structures, the determination of the stability of objects and the analysis of rotational motions.

Below are several simulations and other educational resources, which can also serve as very illustrative examples. In addition, a selection of books and courses is included to help you broaden your knowledge of this subject.

Turning a door

In this simulation, the moment required to rotate the door is fixed. Observe how the force to be applied varies when moving the handlebar or changing the angle of application of the force. How to minimize the force required?

Rocker arm

In this simulation, different masses can be placed in various positions on the rocker arm. See how by changing the masses and the distances to the center of each side, different balanced configurations can be achieved.

Tension and position

Change the position of the mass and observe how the tension forces on the two ropes change. In which position do the tensions equalize?

Suspension bridge

Balancing Act

Play with objects on a seesaw to learn about balance. Test what you've learned with the balance challenge game.

File

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Lever

A lever is a tool that allows us to transmit force using a bar and a fulcrum. See what force is required to balance the mass depending on the distance to the fulcrum.