It may be worth it to decide how we define ‘unstoppable force’ and ‘immovable object’.
An Immovable Object has 0 velocity:
v = 0
Acceleration is the time derivative of velocity:
a = d/dt(v(t))
a = d/dt(0)
a = 0
And we know that
a = Fnet / m
An object with infinite mass would satisfy this equation, but an object with no net force would too. We could add a correction force that will satisfy the constraint of 0 net force.
|Fnet| = 0
∑Fi = 0
Fcorrection + … = 0
To satisfy Newton’s 3rd law, we would need a reaction force to our correction force somewhere, but let’s not worry about that for now.
A physics definition of ‘Unstoppable Force’ is:
|Funstoppable| =/= 0
In this case the gravitational force fits this description, given a few constraints
Fg = Gm∑ Mi / xi2
As long as the gravitational constant G is not 0, our object has mass, and
∑ Mi / xi2 =/= 0, then
|Fg| > 0
But this does feel kinda like cheating because it’s not really what people mean by ‘unstoppable force’. the other way to define it is just immovable object in a different reference frame.
a = 0, |v| > 0
I’m gonna stop here because this is annoying to type out on mobile
It may be worth it to decide how we define ‘unstoppable force’ and ‘immovable object’.
An Immovable Object has 0 velocity:
v = 0
Acceleration is the time derivative of velocity:
a = d/dt(v(t))
a = d/dt(0)
a = 0
And we know that
a = Fnet / m
An object with infinite mass would satisfy this equation, but an object with no net force would too. We could add a correction force that will satisfy the constraint of 0 net force.
|Fnet| = 0
∑Fi = 0
Fcorrection + … = 0
To satisfy Newton’s 3rd law, we would need a reaction force to our correction force somewhere, but let’s not worry about that for now.
A physics definition of ‘Unstoppable Force’ is:
|Funstoppable| =/= 0
In this case the gravitational force fits this description, given a few constraints
Fg = Gm∑ Mi / xi2
As long as the gravitational constant G is not 0, our object has mass, and
∑ Mi / xi2 =/= 0, then
|Fg| > 0
But this does feel kinda like cheating because it’s not really what people mean by ‘unstoppable force’. the other way to define it is just immovable object in a different reference frame.
a = 0, |v| > 0
I’m gonna stop here because this is annoying to type out on mobile