Calculate gravitational acceleration without mass of both objects

AI Thread Summary
Calculating gravitational acceleration without knowing the mass of both objects presents challenges, as gravitational force (Fg) depends on mass. The user attempts to relate force and acceleration through the equations F = m*a and Fg = 𝜸(m1*m2)/r^2, leading to an expression for acceleration. They calculate an average acceleration of 4.9 m/s^2 for a meteoroid approaching Earth, but express uncertainty about the accuracy of their calculations. The discussion hints at the conservation of energy as a potential method to relate speeds at different positions. The conversation emphasizes the complexities of gravitational interactions and the need for further clarification on the calculations.
IAmBadAtMath
Messages
2
Reaction score
0
Homework Statement
A meteroide travelling at earth at a speed of 8.5km/s. It is currently 12R (earth radius) from the center of the Earth. At which speed does the meteroite crash into Earth?
Relevant Equations
Earths Radius (R) = 6,4*10^24m
Mass of earth (m2): 6*10^24kg
Mass of meteroide (m1): ?
𝜸 = Gravitational constant (6.67408*10^-11Nm^2/kg^2)
r: radius( in this case 12R)

Fg = 𝜸(m1*m2)/r^2
F=m*a
I haven't gotten anywhere. I don't find it possible to calculate this since Fg varies based on the Mass of the meteroide and because of that it will change acceleration. I thought about trying to remove m1 by making F=m*a the same as 𝜸(m1*m2)/r^2 since I think they are the same force.

m*a= 𝜸(m1*m2)/r^2
a = 𝜸*m2/r^2

I then thought about getting the avarage acceleration out of it since its acceleration will increase the closer it gets to earth
𝜸*6*10^24kg/(12* 6.4*10^24m)^2 = 0.068m/s^2
gravity at the surface of the Earth is 9.81 m/s^2

(0.068m/s^2 + 9.81m/s^2)/2 = 4.9m/s^2

At this point i don't know what I can do anymore. I have what I think is the avarage acceleration for the meteroide, but I don't know what to do next and I honestly don't even know If I have calculated right at all.
 
Physics news on Phys.org
You are trying to relate a known speed at position 12 R with an unknown speed at position R. What kind of equation would do that? Hint: What quantity is conserved?
 
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 .
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Trying to understand the logic behind adding vectors with an angle between them'
My initial calculation was to subtract V1 from V2 to show that from the perspective of the second aircraft the first one is -300km/h. So i checked with ChatGPT and it said I cant just subtract them because I have an angle between them. So I dont understand the reasoning of it. Like why should a velocity be dependent on an angle? I was thinking about how it would look like if the planes where parallel to each other, and then how it look like if one is turning away and I dont see it. Since...
Back
Top