Skip to main content
Ch 13: Gravitation
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610Non è quello che usi tu?Cambia libro di testo
Capitolo 13, Problema 32a

A uniform, spherical, 1000.0-kg shell has a radius of 5.00 m. Find the gravitational force this shell exerts on a 2.00-kg point mass placed at the following distances from the center of the shell: (i) 5.01 m, (ii) 4.99 m, (iii) 2.72 m.

Guida verificata passo dopo passo
1
Understand the problem: We need to find the gravitational force exerted by a spherical shell on a point mass at different distances from the center of the shell. The shell has a mass of 1000.0 kg and a radius of 5.00 m, and the point mass is 2.00 kg.
Recall the shell theorem: For a point mass outside a spherical shell, the shell's gravitational force acts as if all its mass were concentrated at its center. For a point mass inside the shell, the gravitational force is zero.
For distance 5.01 m (outside the shell): Use the formula for gravitational force, \( F = \frac{G \cdot m_1 \cdot m_2}{r^2} \), where \( G \) is the gravitational constant, \( m_1 \) and \( m_2 \) are the masses, and \( r \) is the distance between the centers of the two masses. Substitute \( m_1 = 1000.0 \text{ kg} \), \( m_2 = 2.00 \text{ kg} \), and \( r = 5.01 \text{ m} \).
For distance 4.99 m (inside the shell): According to the shell theorem, the gravitational force inside a uniform spherical shell is zero. Therefore, the force on the point mass is zero.
For distance 2.72 m (inside the shell): Again, apply the shell theorem. Since the point mass is inside the shell, the gravitational force exerted by the shell is zero.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
4m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Newton's Law of Universal Gravitation

Newton's Law of Universal Gravitation states that every point mass attracts every other point mass in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. This law is essential for calculating the gravitational force between the shell and the point mass.
Video consigliato:
Percorso guidato
04:05
Universal Law of Gravitation

Shell Theorem

The Shell Theorem, derived from Newton's laws, states that a uniform spherical shell of matter exerts no net gravitational force on a particle located inside the shell. For a particle outside the shell, the shell's gravitational effect is as if all its mass were concentrated at its center. This theorem simplifies the calculation of gravitational forces at different distances from the shell.
Video consigliato:
Percorso guidato
13:46
Parallel Axis Theorem

Gravitational Field Inside and Outside a Spherical Shell

The gravitational field inside a spherical shell is zero due to the Shell Theorem, meaning a point mass inside experiences no gravitational force from the shell. Outside the shell, the gravitational field behaves as if the shell's mass were concentrated at its center, allowing the use of Newton's Law of Universal Gravitation to calculate the force at distances greater than the shell's radius.
Video consigliato:
Percorso guidato
9:26
Gravitational Force Inside the Earth
Pratica correlata
Domanda del libro di testo

The dwarf planet Pluto has an elliptical orbit with a semimajor axis of 5.91 × 1012 m and eccentricity 0.249. During Pluto's orbit around the sun, what are its closest and farthest distances from the sun?

3031
views
Domanda del libro di testo

A uniform, spherical, 1000.0 kg1000.0\(\text{ kg}\) shell has a radius of 5.00 m5.00\(\text{ m}\). Sketch a qualitative graph of the magnitude of the gravitational force this sphere exerts on a point mass m as a function of the distance rr of mm from the center of the sphere. Include the region from r=0r = 0 to r→∞r\(\to\)\(\infty\).

1751
views
Domanda del libro di testo

A thin, uniform rod has length L and mass M. A small uniform sphere of mass m is placed a distance x from one end of the rod, along the axis of the rod (Fig. E13.34). Calculate the gravitational potential energy of the rod–sphere system. Take the potential energy to be zero when the rod and sphere are infinitely far apart. Show that your answer reduces to the expected result when x is much larger than L.

730
views
Domanda del libro di testo

In 2004 astronomers reported the discovery of a large Jupiter-sized planet orbiting very close to the star HD 179949 (hence the term 'hot Jupiter'). The orbit was just 1/9 the distance of Mercury from our sun, and it takes the planet only 3.09 days to make one orbit (assumed to be circular). How fast (in km/s) is this planet moving?

2803
views
Domanda del libro di testo

A uniform, solid, 1000.0-kg sphere has a radius of 5.00 m. Find the gravitational force this sphere exerts on a 2.00-kg point mass placed at the following distances from the center of the sphere: (i) 5.01 m, (ii) 2.50 m.

1256
views
Domanda del libro di testo

On October 15, 2001, a planet was discovered orbiting around the star HD 68988. Its orbital distance was measured to be 10.5 million kilometers from the center of the star, and its orbital period was estimated at 6.3 days. What is the mass of HD 68988? Express your answer in kilograms and in terms of our sun's mass.

2599
views