The force F is acting at a perpendicular distance D from the center of mass CM. The force F will generate a torque(consequentelly an angular acceleration) and a force 'f' at the box center of mass. So my question is: what is the value of 'f'?!?
Thanks....
What is the value of 'f' on this force system?!?
Author
Hey I have one question that can be a stupid one but....here we go...:P
Look a this image:
The force F is acting at a perpendicular distance D from the center of mass CM. The force F will generate a torque(consequentelly an angular acceleration) and a force 'f' at the box center of mass. So my question is: what is the value of 'f'?!?
Thanks....
The force F is acting at a perpendicular distance D from the center of mass CM. The force F will generate a torque(consequentelly an angular acceleration) and a force 'f' at the box center of mass. So my question is: what is the value of 'f'?!?
Thanks....
My rigid body physics are a little rusty (it's been a few semesters), but I'd say to use some sort of conservation of energy equations. See how much energy goes into the rotational component, and the remainder goes into the translational component (assuming no loss of energy to things like friction).
This looks like it might be a 'trick question' of sorts, intended to challenge your intuition. I don't have a solid enough background in physics to say for sure, but I think it may be that the value of f can be derived very simply (in the simplest way possible, in fact) from another value in the example.
I remember this type of question from my own physics midterms, as long as the center of mass isn't fixed there's more to the problem than meets the eye. Now I can't remember for sure which is why I suggested using conservation of energy equations. If only I had saved those midterms!
Quote:f = FHey, don't just give him the answer! :-) Better to give a hint and get him going in the right direction (what is what I was attempting to do, more or less...).
Its gonna depend on the moment of inertia of the bar is... If the moment of inertia is 0 then f will be equal to 0 also, the force F will go in to rotating the bar rather than moving it sideways. If the moment of inertia is close to infinity, then f will equal -F and all the force F will go towards moving the bar sideways. In reality it will be a combination of the two, i'm afraid I don't know the equations off the top of my head. Maybe have a read through this: http://en.wikipedia.org/wiki/Moment_of_inertia
The principle of moments, ah bless, brings back memories.
This comes down to an equation like this:
Mass1 = 3.0N * 0.30cm
Mass1 = 1.0Nm
So, it should be:
f = F * D
Hope that helps.
This comes down to an equation like this:
Mass1 = 3.0N * 0.30cm
Mass1 = 1.0Nm
So, it should be:
f = F * D
Hope that helps.
Author
When you think about the wheel of a car you can assume that f = F because when the motor apllies a torque in the wheel, it applies a force with a magnitude of torque/wheel radius in the ground and if the wheel dont slide the force it is appling on the ground will be returned thanks to the static friction force and if it slides, a force with the magnitude of the maximum sliding friction force will be returned. This force(traction) is transmitted to the wheel's center of mass with the same magnitude.
I also thought about this: if D=0, f=F(of course!), so f=F/(D+1) ... :D ... not sure about this....I think its wrong :P
I also thought about this: if D=0, f=F(of course!), so f=F/(D+1) ... :D ... not sure about this....I think its wrong :P
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