Pulley Constraints: How to Carry Load Easily

[Rohan Sahuji]

How do pulleys help in carrying load?
may be to reduce efforts.

 

[HallsofIvy]

All "elementary machines" work on the principal of "conservation of energy". There is no "conservation of force" law- you can reduce the foirce necessary to do a job by increasing the distance over which you apply the force since "work (energy)= force times distance",.

 

[russ_watters]

AKA "mechanical advantage" http://en.wikipedia.org/wiki/Mechanical_advantage

 

[tatiana]

Pulleys allown work to be done "easier" they change the direction of an applied force, transmit rotational motion that therefore adhears to mechanical advantage