40
Pulley system, demonstrating how pulleys facilitate the lifting of heavy weights (2004) (upload.wikimedia.org)
submitted 4 months ago by to c/physics@mander.xyz
11 comments fedilink hide all child comments
 

A gun tackle has a single pulley in both the fixed and moving blocks with 2 rope parts dividing the load of 100N. The mechanical advantage is 2, requiring a force of only 50N to lift the load.

Author: César Rincón

CC BY-SA 3.0

you are viewing a single comment's thread
view the rest of the comments
[–] 9 points 4 months ago (4 children)

Somewhere between 100-150 N of downward force, depends on the angle that the rope on the left is being pulled at

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 4 child comments
    •
  • [–] 4 points 4 months ago (1 child)

    I don't think it can get as low as 100N, for that you would have to pull completely upwards. The shadow in the image implies a ceiling, so ~112N if we take 90° as the max angle. The 150N would be the only case with a completely downward force, if you pull at another angle the resulting force vector will be angled as well.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 1 child comment
    •
  • [–] 1 point 4 months ago* (1 child)

    Wouldn't it depend on how fast that rope is pulled too, adding in the acceleration of the mass (or are you considering that with your range of 100-150)?

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 1 child comment
    •
  • [–] 3 points 4 months ago

    Nope. Right now the system is balanced, the rope is not being pulled just hold. To pull the weight up you need more than 50N, plus a bit more if we take into consideration the friction in the pulleys and in the rope itself.

  • permalink
  • fedilink
  • source
  • parent