Gravitational Constant and Movement due to Attraction

In summary, the student proposes to measure the gravitational constant G by suspending two spherical objects from the ceiling of a tall cathedral and measuring the deflection of the cables from the vertical. They draw a free body diagram for one of the objects and find that the gravitational force on the object is mg and the object hangs at an angle θ.
  • #1
kk727
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Homework Statement


A student proposes to measure the gravitational constant G by suspending two
spherical objects from the ceiling of a tall cathedral and measuring the deflection of the cables
from the vertical. Draw a free-body diagram of one of the objects. If two 100.0-kg objects are
suspended at the lower ends of cables 45.00 m long, and the cables are attached to the ceiling
1.000 m apart, what is the separation of the objects?


Homework Equations


http://tycho.physics.wisc.edu/courses/phys201/fall06/Discussion/Disc18Solution.pdf


The Attempt at a Solution


Honestly had no idea. The solution and equations are on the website above; I tried to figure it out based on that, but I was lost immediately and did not know what to do. Any help explaining it would be much appreciated.
 
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  • #2
Can we see the free body diagram?
 
  • #3
We weren't given one :/
All that was given to us was the question, above. I found the website myself which is supposedly the solution. And I wouldn't even know where to begin with the FBD.
 
  • #4
Okay, need help with the free body diagram.
Draw a picture of the hanging mass. And the other one hanging beside it.
On one of them, draw an arrow downward and write F = mg on it.
Draw an arrow sideways to show the gravitational force of the other mass on it. Do you have the formula for the force of one mass on another?

Oh, have to draw the diagram again because the sideways force will pull the mass slightly toward the other one, so the mass hangs at an angle, not straight down. Also need an arrow along the angled string to indicate the force of the string. Mark the angle θ.

Show us your FBD and someone will help you with the next step, which is to write that the sum of the horizontal forces is zero and
the sum of the vertical forces is zero.
 
  • #5
We went over this in class, sorry I couldn't respond quicker, but I understand it now! I was overthinking it wayyy too much!
Thank you for offering your help, though!
 

1. What is the Gravitational Constant?

The Gravitational Constant, denoted by the symbol G, is a physical constant that represents the strength of the gravitational force between two objects with mass. It is an important value in the equation for calculating the force of gravity, which is given by F = (G*m1*m2)/r^2, where m1 and m2 are the masses of the two objects and r is the distance between them.

2. How is the Gravitational Constant measured?

The Gravitational Constant is a difficult value to measure accurately, but it is usually determined experimentally by measuring the gravitational force between two known masses at a known distance. This is often done using a torsion balance, which measures the twisting of a wire caused by the gravitational force between two masses.

3. Why is the Gravitational Constant important?

The Gravitational Constant is important because it helps us understand and predict the movement of objects due to gravitational attraction. It is a fundamental constant in many equations used in physics, including Newton's Law of Universal Gravitation and Einstein's Theory of General Relativity.

4. Does the Gravitational Constant ever change?

The Gravitational Constant is currently believed to be a constant value, meaning it does not change with time or location. However, some theories suggest that it may vary in extreme conditions, such as in the early universe or near black holes. These theories are still being studied and have not been definitively proven.

5. How does the Gravitational Constant affect the movement of objects?

The Gravitational Constant, along with the masses of the objects and the distance between them, determines the strength of the gravitational force between two objects. This force is what causes objects to move towards each other, such as the Earth and Moon orbiting around each other. The value of G also affects the speed and trajectory of this movement, as seen in the equations for calculating gravitational force and acceleration.

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