Calculating Gravitational Force on a Point Mass in the Presence of a Cavity

Click For Summary
SUMMARY

The discussion focuses on calculating the gravitational force acting on a point mass located within a cavity in a larger mass. The key equation presented is r=1/(M-m)*Ʃmr=1/(M-m)*4/3ρR'^3*r, where 'm' represents the mass of the cavity, 'R'' is the radius of the cavity, and 'r' denotes the position of the center of mass. The challenge lies in determining the radius of the cavity (R') to solve for the gravitational force. The problem suggests modeling the force as a combination of contributions from both the larger sphere and a negative contribution from the smaller cavity.

PREREQUISITES
  • Understanding of gravitational force calculations
  • Familiarity with the concept of center of mass
  • Knowledge of density and volume relationships in physics
  • Ability to manipulate algebraic equations involving multiple variables
NEXT STEPS
  • Study the principles of gravitational force in spherical distributions
  • Learn about the shell theorem and its application in gravitational calculations
  • Explore methods for calculating center of mass in composite bodies
  • Investigate the effects of cavities on gravitational fields in physics literature
USEFUL FOR

Students studying physics, particularly those focusing on gravitational forces and mechanics, as well as educators seeking to explain complex gravitational interactions involving cavities.

maurice2705
Messages
6
Reaction score
0

Homework Statement


The question is presented as picture.


Homework Equations


We do not have the radius of the cavity and the position of the m. How can we find the force acted on it?


The Attempt at a Solution


r=1/(M-m)*Ʃmr=1/(M-m)*4/3ρR'^3*r where m is the mass of cavity ,R' is the radius of the cavity and r is the position of center of mass. But I can't find R'.
 

Attachments

  • Gravitation force.jpg
    Gravitation force.jpg
    22.5 KB · Views: 494
Physics news on Phys.org
Can you solve this problem if there was no cavity? If so, perhaps you can think of a way to model the problem so that the force on the point mass is the sum of two contributions, one from the big sphere and a "negative" from the small sphere?
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
5K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 4 ·
Replies
4
Views
8K
  • · Replies 21 ·
Replies
21
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 16 ·
Replies
16
Views
11K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
Replies
335
Views
17K