3 ms·
It’s been a while since high school physics, so I may be way off, but you only need to overcome the static friction of the object and surface. It’s the reason
by nkrisc 4y ago
It’s been a while since high school physics, so I may be way off, but you only need to overcome the static friction of the object and surface.
It’s the reason I can push a large piece of furniture across a floor even though I could never lift it myself.
- Waterluvian 4y agoI think you’re right and my intuition is way off. Now I’m curious if the load is ever going to be greater than a dead lift, assuming no edge cases like being blocked behind a boulder. Ie. Just general ground friction and some incline plane angle less than 90deg.
- invalidator 4y agoThat's determined by the coefficient of friction between the load and the surface. A coefficient of 1 means the force to drag is equal to the normal force (ie, the dead lift). Most things (including moose fur on soil) have a coefficient < 1, but it's not hard to engineer combinations > 1, such as race tires on asphalt.
- gfna 4y agoI have been waiting for being able to use this link for some time now. Perhaps the results of dragging sheep are correlated: https://pubmed.ncbi.nlm.nih.gov/12507336/ https://pubmed.ncbi.nlm.nih.gov/12507336/
- jameshart 4y agoFor the inclined plane scenario, if you’re applying a force horizontally (eg by dragging with a rope) and the object has to slide up and over an inclined bump… even a frictionless incline of 45° will require you to pull horizontally with the more force than the object’s weight in order to get it to move.
- cbsks 4y agoYes! The coefficient of friction can be greater than 1. For example, clean and dry rubber has a static coefficient of friction of 1.16, meaning that it takes 1.16x the force to move an object than the object exerts on the ground. https://www.engineeringtoolbox.com/friction-coefficients-d_778.html https://www.engineeringtoolbox.com/friction-coefficients-d_7... (I think I’m correct here, but this is just from a quick google search and my very fuzzy recollection of high school physics)
- jameshart 4y agoValid for a spherical moose on a smooth plane with constant coefficient of friction, sure. But an object dragged across a real surface will catch on things, and the force to overcome that is going to depend on the breaking strain of the objects and the elastic coefficients required to deform them. That’s the reason that even a winch rated to the weight of your sofa can’t pull it through a doorway that’s too small for it.
- nkrisc 4y ago> But an object dragged across a real surface There are many different kinds of real surfaces. A dead moose also has more give than a sofa.