Using Gravitational Force Equilibrium to Calculate M2/M1 Ratio

AI Thread Summary
The discussion focuses on calculating the M2/M1 mass ratio using gravitational force equilibrium between two point masses and a test mass. The user has derived an equilibrium position of 0.404L and set up the gravitational force equations accordingly. They canceled out common terms but are unsure how to proceed with finding the mass ratio. The user expresses frustration and seeks clarification on manipulating ratios in algebra. The conversation highlights the challenges of applying theoretical concepts to practical calculations in physics.
erykah722
Messages
7
Reaction score
0

Homework Statement



Here is the objective: To experiment with the resultant of two gravitational forces. In particular, you will find the equilibrium position for a test mass located on a line between two point masses.

Here are the instructions:
(1) Drag the test mass (red disk) to an arbitrary point on the line and release. Note the value given for x/L, where x is the distance measured from the center of M1 to the center of the test mass.
(2) Repeat (1), but start the test mass farther away from the mass to which it was attracted.
(3) Continue adjusting the starting position of the test mass until you see the message close enough! Think about how to do that in the most efficient way.
(4) From your latest value of x/L, you can compute the mass ratio M2/M1, without needing to know either L or the value of the test mass. You will have to perform a short derivation to get the simple equation you need. (Hint: start by setting the two gravitational forces acting on the test mass equal to one another.)

I got .404L for the equilibrium value.

Homework Equations



F= M*m*G/r2

The Attempt at a Solution



I set the equations up as:

M*m1*G/0.4042 = M*m2*G/0.5962

I then canceled out the M and G on each equation because they are equal and am left with

m1/0.163 = m2/0.355

I'm stuck here. Am I even doing this right?
 
Physics news on Phys.org
This is just basic algebra, if you have an equation that reads x/a = y/b and you want the ratio of y/x, how would you do that one?
 
...Wow. I'm sorry, I've been really stressed out. Now I'm embarrassed. Thank you though!
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top