Name: calculating work from multiple forces
Uploaded: 2023-05-16T08:18:41.000Z
Duration: 1 min 3 s
Channel: JoVE
Description: Calculating work from multiple forces can be done in two ways, and both methods give the same result. One method finds the work done by each force first. The other method finds the net force by adding the force vectors first.

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Physical Science

Energy

PS.PSc.7.3

Work Done by Many Forces

Considere un tractor de equipaje que tira de un carro de equipaje con una fuerza de 10.000 N en un ángulo de 30 grados. Si el carro ofrece una fricción de 2.000 N mientras es remolcado, ¿cuál es el trabajo realizado en el carro para desplazarlo 10 m en línea recta?
Se dibuja un diagrama de cuerpo libre para obtener una comprensión clara de las fuerzas.
Las fuerzas perpendiculares al movimiento del carro no causan el desplazamiento del carro, por lo que esas fuerzas no realizan ningún trabajo. 
Las fuerzas en la dirección x son el componente de la fuerza de tracción y la fuerza de fricción, que se suman vectorialmente.
El trabajo total realizado es la fuerza resultante a lo largo del desplazamiento multiplicada por el desplazamiento.
Alternativamente, el trabajo realizado por cada fuerza se puede calcular primero y luego sumar.
El trabajo realizado por las fuerzas perpendiculares es cero. La fuerza de tracción y la fuerza de fricción no son perpendiculares al desplazamiento y, por lo tanto, contribuyen al trabajo total.

<ol>
	<li>Young, H.D y Freedman, R.A. (2012). Física Universitaria con Física Moderna. San Francisco, CA: Pearson: sección 6.1; páginas 180-181.</li>
</ol>

trabajo realizado por muchas fuerzas

El trabajo total realizado sobre un objeto actuado por múltiples fuerzas puede ser calculado usando dos métodos que dan el mismo resultado. En un método, primero se calcula el trabajo realizado por cada fuerza. Luego, esos valores se suman algebraicamente para calcular el trabajo total realizado por todas las fuerzas. En el segundo método, la fuerza neta se calcula primero mediante una suma vectorial de todas las fuerzas. Luego, se obtiene el trabajo realizado por esta fuerza. Dado que las fuerzas perpendiculares al desplazamiento no realizan trabajo, no contribuyen al trabajo realizado sobre el objeto. Simplemente, pueden ser ignoradas en el cálculo en el primer método. Sin embargo, en el segundo método, primero deben ser consideradas para calcular el vector de fuerza neta, y solo entonces se ve que su contribución es cero. Si las fuerzas mutuamente opuestas actúan sobre el centro de masa del objeto, contribuyen con trabajos positivos y negativos diferentes en el primer método. A través de la suma algebraica, se encuentra que el trabajo total realizado sobre el objeto es positivo o negativo dependiendo de cuál de las fuerzas es de mayor magnitud. En el segundo método, primero se obtiene la fuerza neta y se determina si actúa a lo largo o en dirección opuesta al desplazamiento neto. Luego, se obtiene el trabajo y se determina si es positivo o negativo dependiendo de su ángulo con respecto al desplazamiento.

Trabajo realizado por muchas fuerzas

El trabajo total realizado sobre un objeto sobre el que actúan múltiples fuerzas se puede calcular utilizando dos métodos que dan el mismo resultado. En un método, el trabajo realizado ...

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Education

Educación

JoVE Core

Physics

Física

Unit 1

Unidad 1

Work and Kinetic Energy

Trabajo y Energía Cinética

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

calculating work from multiple forces

Calculating work from multiple forces can be done in two ways, and both methods give the same result. One method finds the work done by each force first. The other method finds the net force by adding the force vectors first.

Calculating Work from Multiple Forces

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Work Done and Kinetic Energy

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work and energy for variable forces

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work-energy theorem for motion along a curve

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work done over an inclined plane

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work done by many forces

Calculating work from multiple forces can be done in two ways, and both methods give the same result. One method finds the work done by each force first. The other method finds the net force by adding the force vectors first.

work done by gravity

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power

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Power describes how fast work is done. In physics, two sprinters can cross the finish line with the same velocity and do the same amount of work, but the one who finishes first has greater power because the work takes less time. Average power is the work done during a time interval divided by that time interval. When the time interval becomes very small, this becomes instantaneous power. That gives the power at a specific moment instead of over a longer stretch of time. Power can also be...

key terms and concepts

Learn how to calculate work when several forces act on an object using force-by-force addition or the net force method, with the same final result.

Calculating Work from Multiple Forces | JoVE K12

physics

JoVE Core Física presenta la teoría y la aplicación de conceptos físicos fundamentales, como la cinemática, dinámica, mecánica de fluidos, estática, ondas y acústica, mediante animaciones audiovisuales concisas y fáciles de entender. Además, los vídeos de científicos en acción muestran la aplicación de los conceptos relacionados en experimentos de investigación clásicos y originales, realizados en laboratorios de todo el mundo.

PS.Phy.6.2

Tennessee Academic Standards

High School

PHYS.PS3.6

Alabama Course of Study Science

9-12.P.2.3.c

Energy Basics

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Conservation of Mechanical Energy

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Non-conservative Forces

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Conservation of Energy

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Use mathematics and computational thinking to explain the Law of Conservation of Energy in a mechanical system in terms of kinetic and potential energy.

PS.PSc.7.2

Work

Work is done when energy is transferred from one object to another. In other words, work is when a force acts on something that undergoes a displacement ...

Positive, Negative, and Zero Work

Work is done on an object when energy is transferred to the object. In other words, work is done when a force acts on a body that undergoes a displacement ...

Work-energy Theorem

According to Newton&#x2019;s second law of motion, the sum of all the forces acting on a particle (net force) determines the rate of change in the ...

Work and Energy for Variable Forces

When an object is acted upon by a variable force, the amount of work done and the change in energy of the object can be more complex to calculate compared ...

Work-Energy Theorem for Motion Along a Curve

The work-energy theorem can be generalized to the motion of a particle along any curved path. The simple argument here is that the curved path can be ...

Work Done Over an Inclined Plane

The center-of-mass framework helps to easily describe the work done on rigid bodies. Since the internal forces in a rigid body do no work, they can be ...

The total work done on an object acted upon by multiple forces can be computed using two methods that give the same result. In one method, the work done ...

Work Done by Gravity

Gravitation is one of the four fundamental forces in nature. The force between objects on Earth and Earth itself is called gravity.
Like other forces, ...

Use mathematics and computational thinking to explain work in terms of the relationship among the applied force to an object, the resulting displacement of the object, and the energy transferred to an object.

Power

The concept of work involves force and displacement; meanwhile, the work-energy theorem relates the net work done on a body to the difference in its ...

Power Expended by a Constant Force

The relationship between work done and the time taken to do it can be explained using the concept of power. For example, several sprinters in a race may ...

Construct an explanation to infer the relationship between work and power, both quantitatively and qualitatively.

PS.PSc.7.4

Analyze energy transfers and transformations within a mechanical system.

Calculating Work from Multiple Forces

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