Physics problems (gravitational acceleration and work)

If so, how do I calculate it? The problem also mentions to integrate, but I'm not sure what to integrate. Any help would be appreciated. In summary, the conversation is about two physics homework problems. The first problem involves finding an expression for the net gravitational acceleration at an arbitrary point and showing how it varies approximately when Z is much larger than other variables. The second problem asks for help in calculating the work required to disassemble the Earth by removing shells of thickness dR and integrating. The person seeking help is unsure how to approach both problems and is seeking guidance on the last parts of each question.
  • #1
Leaping antalope
44
0
Need help with my physics homework.

1. Consider three masses that lie in the X,Y plane. The first mass, m1 lies at the origin, second mass, m2 lies at (0, Y2) and let the third mass, m3 lies at (X3, 0). Find an expression for the net gravitational acceleratoin at an arbitrary point in pace, (X,Y,Z) and show that if Z is much larger than Y2, X3, X, and Y that the acceleratoin varies approximately as Z^(-2).

2. How much work is required to dissemble the Earth. Assume that the planet is homogeneous with density p and radius R. Calculate te work required to remove shells of thickness dR from the planet and then integrate.
 
Physics news on Phys.org
  • #2
Do you maybe have any ideas on how to approach the questions at least??
It will increase the chances of getting a useful response to your problem.
 
  • #3
Leaping antalope said:
Need help with my physics homework.
1. Consider three masses that lie in the X,Y plane. The first mass, m1 lies at the origin, second mass, m2 lies at (0, Y2) and let the third mass, m3 lies at (X3, 0). Find an expression for the net gravitational acceleratoin at an arbitrary point in pace, (X,Y,Z) and show that if Z is much larger than Y2, X3, X, and Y that the acceleratoin varies approximately as Z^(-2).

For this problem, I found out the three acceleration vectors to m1, m2, and m3. Then I added the three vectors together and got an expression for a net gravitational acceleration. But I don't konw how to do the last part of the question. When Z is much larger than Y2, X3, X, and Y, I tried to cancel the small variables but it didn't work.



Leaping antalope said:
2. How much work is required to dissemble the Earth. Assume that the planet is homogeneous with density p and radius R. Calculate te work required to remove shells of thickness dR from the planet and then integrate.

For this problem, I know that dw=F (dot product) ds. In this problem, ds is the radius of earch. But I'm not sure what F is. Is it the gravitational force?
 

1. What is gravitational acceleration?

Gravitational acceleration is the acceleration due to the force of gravity on an object. It is a measure of how quickly an object falls towards the surface of the Earth, and is approximately 9.8 meters per second squared.

2. How is gravitational acceleration calculated?

Gravitational acceleration is calculated using the equation a = F/m, where a is acceleration, F is the force of gravity, and m is the mass of the object. In most cases, the force of gravity can be approximated as the product of the mass of the object and the gravitational constant, 9.8 m/s².

3. What is the relationship between mass and gravitational acceleration?

The relationship between mass and gravitational acceleration is inverse. This means that as the mass of an object increases, its gravitational acceleration decreases. This is because the larger the mass, the more force is required to accelerate it.

4. How does altitude affect gravitational acceleration?

As altitude increases, gravitational acceleration decreases. This is because the further an object is from the center of the Earth, the weaker the force of gravity acting on it. However, this effect is minimal at everyday altitudes and is only significant at extreme heights, such as in orbit.

5. What is work in physics?

In physics, work is defined as the product of force and displacement. This means that work is done when a force is applied to an object and the object moves in the direction of the force. Work is measured in joules (J) and is a scalar quantity.

Similar threads

  • General Discussion
3
Replies
99
Views
5K
  • Advanced Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
773
  • Advanced Physics Homework Help
Replies
8
Views
2K
Replies
11
Views
2K
Replies
16
Views
772
  • Classical Physics
Replies
7
Views
721
Replies
2
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
4K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
1
Views
1K
Back
Top