Name: free-body diagrams for force analysis
Uploaded: 2023-09-22T11:49:20.000Z
Duration: 1 min 28 s
Channel: JoVE

K12 Standards

Next Generation Science Standards

High School

Physical Science

motion-and-stability-forces-and-interactions

Motion and Stability: Forces and Interactions

HS-PS2-3

Free-body Diagram

La representación visual de todas las fuerzas que actúan sobre la partícula se denomina diagrama de cuerpo libre o diagrama de fuerzas. Transforma problemas complejos en representaciones simples.
En un diagrama de cuerpo libre, la dirección de las flechas indica la dirección de las fuerzas, mientras que la longitud de las flechas representa la magnitud de las fuerzas.
Considere un carro estacionario en el que se apilan dos cajas de cartón.
Aquí, se puede suponer que los dos sistemas de interés, el cuadro uno y el cuadro dos, son sistemas aislados y se pueden representar mediante un diagrama de cuerpo libre en forma de un contorno simple o un punto.
Las fuerzas que actúan sobre la caja uno son la fuerza gravitatoria, que define su peso, y la fuerza normal de contrapeso debida a la caja dos.
De manera similar, las fuerzas en la caja dos son su propio peso, la fuerza normal debida al carro y el peso de la caja uno.
Los diagramas de cuerpo libre juegan un papel integral en el proceso de resolución de problemas como transición de una situación física específica a una ecuación matemática abstracta en mecánica.

<ol>
	<li>Hibbeler, R.C. (2016). Ingeniería Mecánica \u2012 Estática y Dinámica. Hoboken, Nueva Jersey: Pearson Prentice Hall. págs. 88</li>
	<li>Cerveza, F.P.; Johnston, E.R.; Mazurek, D.F.; Cromwell, P.J. y Self, B.P. (2019). Mecánica vectorial para ingenieros: estática y dinámica. Nueva York: McGraw-Hill. págs. 170-171</li>
</ol>

diagrama de cuerpo libre

En mecánica, entender el movimiento de los objetos es esencial, y una herramienta que ayuda a resolver este problema es el diagrama de cuerpo libre. Es una representación gráfica simple, pero poderosa que representa de manera concisa todas las fuerzas que actúan sobre un objeto. Un diagrama de cuerpo libre puede representar un objeto estacionario o en movimiento, y se utiliza en mecánica para explicar la causa del movimiento de un objeto. Un diagrama de cuerpo libre transforma un problema complejo en una representación simple, lo que facilita la comprensión de las fuerzas esenciales que actúan sobre un objeto, lo que lleva a una ecuación matemática. En muchos casos, la ecuación sería extremadamente compleja de derivar sin utilizar diagramas de cuerpo libre. Para hacer un diagrama de cuerpo libre, comienza seleccionando el objeto o sistema bajo inspección, aislándolo de su entorno, y dibujándolo como un punto o un simple contorno. A continuación, representa todas las fuerzas externas esenciales que actúan sobre el objeto o sistema de interés con flechas. La dirección de las flechas representa la dirección de la fuerza, mientras que la longitud de las flechas representa la magnitud de la fuerza. Es importante tener en cuenta que en un diagrama de cuerpo libre, la velocidad y la aceleración no se representan, pero se pueden inferir a partir de las fuerzas aplicadas al objeto. Algunos tipos comunes de fuerzas que se pueden representar en un diagrama de cuerpo libre incluyen el peso, la fuerza normal, la tensión, la fricción y la fuerza aplicada. El peso se refiere a la fuerza de la gravedad que actúa sobre el objeto, generalmente representada por una flecha que apunta hacia abajo. La fuerza normal es la fuerza entre dos objetos cuando entran en contacto entre sí; esta fuerza actúa en dirección opuesta al peso del objeto. La tensión generalmente se representa con una flecha que apunta lejos del objeto en la dirección de la fuerza, y la fricción es la fuerza que resiste el deslizamiento entre superficies. Por último, la fuerza aplicada se refiere a la fuerza aplicada al objeto por un agente externo, como un empuje o una tracción. Las fuerzas aplicadas se representan con una flecha que apunta en la dirección de la fuerza. Considera un carro estacionario, sobre el cual se apilan dos cajas de cartón. Los dos sistemas de interés, caja uno y caja dos, se pueden considerar sistemas aislados y se pueden representar utilizando un diagrama de cuerpo libre. Las fuerzas que actúan sobre la caja uno son la fuerza gravitatoria, que define su peso, y la fuerza normal de contrapeso debido a la caja dos. De manera similar, las fuerzas sobre la caja dos son su peso, la fuerza normal debido al carro y el peso de la caja uno.

Diagrama de cuerpo libre

En mecánica, comprender el movimiento de los objetos es esencial, y una herramienta que ayuda a resolver este problema es el diagrama de cuerpo libre. Es un simple pero ...

Education

Educación

JoVE Core

Mechanical Engineering

Ingeniería Mecánica

Unit 1

Unidad 1

Equilibrium of a Particle

Equilibrio de una partícula

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

free-body diagrams for force analysis

Free-body diagrams help analyze the forces acting on an object in mechanics. They give a simple picture of a stationary or moving object and show why it moves the way it does. By turning a complex situation into a clear sketch, they make it easier to write the equation needed to solve the problem.

To draw a free-body diagram, first choose the object or system you want to study. Then isolate it from its surroundings and draw it as a dot or a simple outline. Add arrows for every important external force. The direction of each arrow shows the direction of the force, and the length shows its size.

A free-body diagram does not show velocity or acceleration. Those quantities are not drawn on the diagram, but they can be inferred from the forces acting on the object. Common forces include weight, normal force, tension, friction, and applied force. Weight is the force of gravity and is usually shown with an arrow pointing downward.

Normal force is the contact force between two objects touching each other. It acts in the direction opposite to the object's weight in many situations. Tension is usually drawn as an arrow away from the object and along the direction of the pull. Friction resists sliding between surfaces. Applied force is an outside push or pull, and it is shown with an arrow in the direction of that force.

A stationary trolley with two cardboard boxes stacked on it gives a clear example. Box one and box two can each be treated as separate isolated systems and shown with their own free-body diagrams. For box one, the forces are gravitational force and the balancing normal force from box two. For box two, the forces are its weight, the normal force from the trolley, and the weight of box one.

Free-Body Diagrams for Force Analysis

equilibrium conditions for a particle

Balanced Forces and Torque in Equilibrium

Equilibrium depends on balanced forces and balanced torque. An object in equilibrium is either at rest or moving with a constant velocity. These two cases are called static equilibrium and dynamic equilibrium. Static equilibrium means the object is not moving. Dynamic equilibrium means the object is moving, but its velocity stays constant. In both cases, the forces acting on the object must balance each other. Different forces can add, subtract, or cancel each other out. When the vector sum...

free-body diagram

Free-body diagrams help analyze the forces acting on an object in mechanics. They give a simple picture of a stationary or moving object and show why it moves the way it does. By turning a complex situation into a clear sketch, they make it easier to write the equation needed to solve the problem. To draw a free-body diagram, first choose the object or system you want to study. Then isolate it from its surroundings and draw it as a dot or a simple outline. Add arrows for every important...

steps for free-body diagram

Free-Body Diagram for Two-Block Motion

A free-body diagram helps analyze two-block motion in mechanics. It shows the forces acting on a system so the net force can be found and the acceleration can be calculated. The example in this lesson uses two blocks linked by a massless string over a frictionless pulley. Block 1 moves across a table while block 2 falls under gravity. The two blocks are treated as one isolated system. External forces are then identified and drawn as vector arrows on the diagram. For block 1, the forces...

free-body diagrams: problem solving

Free-Body Diagrams on Inclined Planes

Free-body diagrams help show the forces acting on an object on an inclined plane. A free-body diagram is a simple drawing that focuses only on the object or system being studied. It leaves out extra details so the force problem is easier to analyze and solve. For an example, a 10 kg block is released on a ramp that is 30° to the horizontal. The coefficient of friction is 0.2. The diagram for this block includes the weight from gravity, the normal force, and the frictional force. These are the...

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Coplanar forces act on an object in the same plane. To analyze this kind of system, each force is resolved into x and y components using Cartesian vector form and vector algebra. This makes it possible to test whether the object is in equilibrium. A coplanar system is in equilibrium when the resultant force is zero. That means the sum of the forces in each direction must also be zero. If the forces do not balance, the object is not in equilibrium and will accelerate in the direction of the net...

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Equilibrium in physics describes how forces act on a body so it stays still or moves at a constant speed. In two-dimensional force systems, equilibrium can be grouped into several categories based on how the forces are arranged. Collinear equilibrium is the simplest case. The forces act along one straight line, so only one force equation is needed in the direction of those forces. The other equations are already satisfied. Coplanar concurrent equilibrium is another category. In this case, all...

key terms and concepts

Learn how free-body diagrams show weight, normal force, tension, friction, and applied force. See how isolating an object simplifies force analysis in mechanics.

Free-Body Diagrams for Force Analysis | JoVE K12

JoVE Core Mechanical Engineering offers concise, easy-to-understand animated videos covering key topics such as equilibrium, forces, truss analysis, and structural mechanics. Explore their real-world applications, and witness these concepts in action through scientist-led experiments.

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HS-PS2-6

Free-Body Diagrams for Force Analysis

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