Recent content by dcb

I now understand your argument about the scale. It seemed to me like the scale is designed to only measure Y forces but I got inconsistent results in an experiment. Intuitively it seems like the X forces are 0 at 0 degrees reach a maximum at 45 and go back to 0 at 90 (at least for H=0). I...

Thank you for joining in this discussion. Every time I try to figure out the X forces it makes no sense to me. I think that if both guys could somehow grab their end of the couch at h/2 instead of the base, everything changes. I'm out of the country in a few days for the month of April so...

This approximates what I see on a scale when I put one end of dumbbell on it and slowly lift the other end.

As berkeman pointed out to me, I have morphed the discussion into something different than the original post so I apologize but I was interested xshovelfighter's observation of inclined push up's and carrying a couch. If you assume the couch has zero height everything you say is correct. The...

When the fork is vertical you fingers are providing zero force.

I suggest you buy a cheap scale. Place a fork on it and it may weight say 20 grams. Now balance the fork vertically on the scale by tapping it with your fingers and it will say 20 grams.

How can the guy at the top of the couch support any weight whatsoever?

Sorry horizonal with only one person.

You clearly do not understand the problem. If the couch is vertical (or horizontal for that matter) the center of mass of the couch is straight down over the guy. There is no way the guy is not carrying 100% of the weight of the couch.

Do you agree that the guy on the lower stair holding the vertical couch is carrying the entire weight?

No, again to be clear, there is no attachment of the ramp to either end. It is not "pinned to the beam". It is simply resting on either side. I'm not attaching the dumbbell to the scale, I'm resting it on the scale. This is the case I'm interested in.

Hi jbriggs444, thanks for responding. Yes I realize how old this post is and I was hoping someone would respond as I'd Iike to discuss this. I happened on to this as I have a dock and was trying to figure out the forces on it as the water level went up and down. I have a bachelor's and...

I should note that the presumption is that the ramp is resting on both ends (which would be the case for couch moving and inclined pushups) and we are trying to understand the forces in the y direction,

@xshovelfighter, I believe you are correct and Tom G's initial post is also correct. I'm not sure why he recanted in his second post. I have also carried a couch down the stairs and you definitely want to be the guy on the upper end. I would also much rather do pushups flat to the ground...