Name: how earth’s shape affects apparent weight
Uploaded: 2023-04-30T11:06:22.000Z
Duration: 1 min 20 s
Channel: JoVE

K12 Standards

Virginia  Standards of Learning

HIgh School

Earth Science

ES.3

ES.3.b

variation-in-acceleration-due-to-gravity-near-the-earth-s-surface

Variation in Acceleration due to Gravity near the Earth's Surface

Considere un objeto de masa m suspendido de una escala de resorte unida a un soporte rígido. En el ecuador de la Tierra, la lectura de la escala, que es la magnitud del peso aparente del objeto, es igual a la magnitud de su peso real menos la magnitud de la fuerza centrípeta.
Sin embargo, si el objeto suspendido de la escala se coloca en alguna otra latitud λ, entonces la fuerza centrípeta que actúa sobre el objeto se dirige hacia el punto P en el eje de rotación, lejos del centro de la Tierra.
Por lo tanto, el peso aparente del objeto es igual al peso real menos el componente coseno de la fuerza centrípeta dirigida hacia el centro de la Tierra.
En general, dividiendo la ecuación por m, la aceleración neta g' del objeto lejos de los polos es menor que la aceleración debida a la gravedad por un factor igual a la aceleración centrípeta.
La Tierra es una esfera oblata que tiene un radio ecuatorial mayor que su radio polar. Por lo tanto, su densidad variable también contribuye a la variación de la aceleración debido a la gravedad.

variación en la aceleración debido a la gravedad cerca de la superficie de la tierra

Un peso aparente de un objeto es su peso medido por una balanza de resorte en su ubicación. Es diferente de su peso real, la fuerza con la que la Tierra lo atrae, debido a la rotación de la Tierra. Matemáticamente, el peso aparente de un objeto es igual a su peso real menos la fuerza centrípeta que lo mantiene en movimiento circular junto con la superficie de la Tierra durante 24 horas. La diferencia entre los pesos real y aparente es proporcional al cuadrado de la velocidad angular de la Tierra. Dado que la velocidad angular de la Tierra es relativamente pequeña y su cuadrado aparece en la diferencia, el efecto neto de la rotación de la Tierra es solo del 0,34% del peso de un objeto. Sin embargo, este efecto disminuye suavemente a medida que uno se mueve desde el ecuador hacia los polos. La variación se formula invocando la geometría simple; dado que cada objeto rota a lo largo de un círculo que abarca la latitud en la que se encuentra, la diferencia entre los pesos real y aparente depende de la latitud del objeto. El efecto máximo se encuentra en el ecuador y el mínimo en los polos. En los polos, el peso aparente es igual al peso real porque los polos de la Tierra no rotan. El radio de la Tierra también contribuye a la diferencia entre el peso real y aparente. La Tierra no es una esfera perfecta; su radio es aproximadamente 30 km mayor en el ecuador en comparación con los polos, debido a que el interior es parcialmente líquido, lo que aumenta el abultamiento de la Tierra en el ecuador debido a su rotación. Por lo tanto, el abultamiento de la Tierra hace que el peso aparente de un objeto sea menor que el peso real por un factor adicional. Se puede mostrar que este factor es comparable al factor relacionado con la rotación de la Tierra. Este texto está adaptado de <a href="https://openstax.org/books/university-physics-volume-1/pages/13-2-gravitation-near-earths-surface">Openstax, University Physics Volume 1, Section 13.2: Gravitation Near Earth's Surface.</a>

Variación en la aceleración debido a la gravedad cerca de la superficie de la Tierra

El peso aparente de un objeto es su peso medido por una balanza de resorte en su ubicación. Es diferente de su verdadero peso, la fuerza con la que el ...

Education

Educación

JoVE Core

Physics

Física

Unit 1

Unidad 1

Gravitation

Gravitación

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

how earth’s shape affects apparent weight

Apparent weight changes slightly on Earth because of rotation and the planet’s shape. Apparent weight is the weight measured by a spring balance at a location. It is different from true weight, which is the force Earth pulls on an object with.

Earth’s rotation reduces apparent weight by adding a centripetal force. Centripetal force is the inward force that keeps an object moving in a circle. The apparent weight equals the true weight minus this force. The difference depends on the square of Earth’s angular speed, so the effect is small. In fact, rotation changes weight by only about 0.34%.

This change also depends on latitude. Latitude is a position north or south of the equator. The effect is largest at the equator and decreases smoothly toward the poles. At the poles, the apparent weight equals the true weight because Earth’s poles do not rotate in the same way.

Earth’s radius adds another small change. Earth is not a perfect sphere. Its radius is about 30 km larger at the equator than at the poles because the planet bulges outward. This bulge comes from Earth’s partly liquid interior and its rotation. The bulging makes apparent weight smaller than true weight by an additional factor, and this factor is comparable to the one caused by rotation.

How Earth’s Shape Affects Apparent Weight

how-earth-s-shape-affects-apparent-weight

gravitation

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acceleration due to gravity on other planets

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variation in acceleration due to gravity near the earth's surface

Apparent weight changes slightly on Earth because of rotation and the planet’s shape. Apparent weight is the weight measured by a spring balance at a location. It is different from true weight, which is the force Earth pulls on an object with. Earth’s rotation reduces apparent weight by adding a centripetal force. Centripetal force is the inward force that keeps an object moving in a circle. The apparent weight equals the true weight minus this force. The difference depends on the square of...

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kepler's third law of planetary motion

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key terms and concepts

Learn why apparent weight changes with latitude on Earth. Explore the effects of rotation, centripetal force, and the planet’s equatorial bulge.

How Earth’s Shape Affects Apparent Weight | 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.

PH.3

PH.3.b

Florida Department of Education

High School

Earth and Space Science

SC.912.E.5

SC.912.E.5.10

SC.912.E.5.11

Texas Essential Knowledge and Skills

PHYS.5

PHYS.5.H

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

Earth and Space Science (ESS)

Earth’s Place in the Universe

E-ESS1-6.

new-york-state-science-learning-standards

New York State Science Learning Standards

Physical Science

HS. Forces and Interactions

HS-PS2-4.

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How Earth’s Shape Affects Apparent Weight

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