1
vote
1answer
45 views

Gravity force and dark energy [duplicate]

If gravity is a fundamental force which bends spacetime and dark energy is energy which stretches spacetime, what is the difference between the terms force and energy?
0
votes
2answers
178 views

Equilibrium - uniform circular motion

Maybe this is a bit of a silly question, but let us pretend we have a pendulum in a ideal universe with no friction, drag, or anomalous forces there to affect it. Additionally, our pendulum is ...
11
votes
2answers
1k views

Is Pauli-repulsion a “force” that is completely separate from the 4 fundamental forces?

You can have two electrons that experience each other's force by the exchange of photons (i.e. the electromagnetic force). Yet if you compress them really strongly, the electromagnetic interaction ...
2
votes
3answers
305 views

Weightlessness by a parabolic flight

Do you actually achieve weightlessness during a parabolic flight? Because I believe I heard somewhere did you achieve 'near-weightlessness' and not 'weightlessness' (if this is true, why is this?) ...
-2
votes
1answer
1k views

Can I just ask what these pulleys-and-constant-lengths problems are called?

I am not sure if this question is appropriate for this section, but I just want to know what these type of questions are called and when do physics majors learn them? These problems have to do with ...
5
votes
2answers
119 views

What is it called when a fluid will “jump” to grab onto an object that comes very close?

I'm doing an experiment where I bring a probe very close to a well full of fluid and then very slowly lower it to obtain some force deformation values. The material behaves very much like a fluid and ...
0
votes
3answers
266 views

Is $f=ma$ an identity?

In his The Principles of Natural Knowledge, Alfred North Whitehead writes that famous $f=ma$ is an identity: It has been popular to define force as the product of mass and acceleration. The ...
4
votes
4answers
1k views

Work done by the Magnetic Force

The magnetic part of the Lorentz force acts perpendicular to the charge's velocity, and consequently does zero work on it. Can we extrapolate this statement to say that such a nature of the force ...