How does something of X kg lift something heavier than X kg?

Question

how does something of X kg lift something heavier than X kg?

1) is this possible in machines, since it is possible in human bodies?

2) how is this possible for humans , and how is it possible for machines?

Answer 1

consider a tettertotter  or  lever

force*distance on one side = force*distance on the other

Answer 2

Yes machines can do it, many examples: levers, pulleys, machines, etc...

Many organisms including humans can lift heavy objects (heavier than themselves). There are many reasons and limitations to this effect... The way your muscles are anchored to bone is such that your limbs act as levers. Imagine instead of attaching your bicep to your forearm, it was attached to a hook and the hook was attached to a 20 lb sand bag. Your muscle may not be able to lift the sand bag, and if it could, not very far. Because your bicep is attached to your forearm, your elbow serves as the fulcrum of the lever allowing you to lift more. For a given muscle mass, having longer forearms increases the amount that you can lift. Thus strength output is not only dependent on muscle mass and tone, it also depends on bone length. Of course it is much easier to change the mass of your muscles (by working out) than it is to change the length of your limbs (drink milk?).  The same principle applies to all your muscles, not just your arms.

Answer 3

1. Yes. a machine could carry more than its weight. (theres a new product in Japan. It is pretty light and can help and average person carry 5-7 rice bags.)

2. It's definitely possibe for humans, probably because we can build up body strength. ( im 20 lbs underweight Idk why but I can carry something that's 2 1/2 times my weight (XD))  It's also probably possible for machines, because it might focus all the weight of the obejct being lifted to the strongest area. (the Japanese machine would grab hold of the object and lit with its "legs".

Answer 4

imagine a surfboard carries a surfer, an air balloon carries a person..

it depends on the medium, you can not lift something heavier than you always, you could carry lift him in water but not in land, in machines, screws do this, like the irrigation in the early civilizations, they use large screws to lift large amounts of water