When carrying something heavy alone (a couch for example) it is either really heavy or seemingly impossible to lift, but when 2 people on each side lift, it suddenly becomes super light, and I think they have all the weight, making me feel guilty. I recently helped someone move and they said they thought the same. Where does all the weight go?
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It gets split in half my guy, if it weights 50lbs then each person is only lifting around 25 depending on the angle. Another factor may be that something is just awkward to pick up alone, our arms are much stronger at certain angles then others.
If you are carrying equally, the weight halves. Halfing the weight of something drastically changes the feeling.
Some of it is also the efficiency of the force you’re generating. Moving a bulky object in your own is difficult, for example this couch. You can’t lift it by yourself, because it’s too long and trying to drag it creates a lot of friction that you’re fighting against. If you could somehow get under the couch dead center, you could probably lift it with effort (like someone deadlifting).
By having two people carrying the weight, putting force in the same direction and avoiding the friction, it becomes that much easier.
This is also why it’s so much easier to lift something “solid” vs dead weight. A 35lb bag of sand is harder to move than a 35lb iron plate because the bag is able to shift around, dragging against you, vs the plate you can carry close to your body.
Math dear redditor. Twice the lifting power means each bears, in theory, half the load. Additionally, awkward and large things are difficult to pick up because we can only do so much work in one spot. A couch for example can be picked up on one side by a person, but the same person cannot easily lift the other side because they are already lifting the first side. Our arms are only so long and our muscles can only balance so much weight so far.
First of all, the other person is taking half the weight, but that’s only part of the story.
When a weight is at the end of a lever, it’s harder to pick up. Try picking up a sledge hammer from the end of the handle, vs the top where the hammer is — it will be easier on the hammer side. Basically, the closer the center of gravity is to the weight’s support, the easier it is to lift because the lever arm is smaller.
So when you try to pick up the couch, most of the weight is far away from you, which makes it more difficult to lift — the other side wants to rotate downward. When you have two people at opposite ends of the couch, the center of gravity of the couch is between the two people, or inside the base (the base being the 4 legs of the people picking up the couch).
If you put both people on the same side of the couch, it will still be very hard to lift because the far side will be at the end of a long lever arm.
The real answer to this needs a picture with force vectors. Hopefully my explanation with just words made some kind of sense.
The problem with lifting a couch is usually not the weight itself but the fact that the center of weight of a couch is usually far from your body. So it is going to tip you forwards making you lean far back and generally make it very hard to carry by yourself. Imagine for example being able to lift the couch up on your head keeping the center of mass right over your feet, it will be much easier to carry.
When two people carry a couch they can put their legs on each side of the center of mass therefore balance it perfectly between them. This makes it so much easier to carry as there is very little effort being put into balancing it and all the effort can be put into lifting it.
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