Question

A movable pulley is to be used for lifting a load of 80 kg. What effort is required?

plzzz explain it with answer​

Answer 1

Answer:

The movable pulley reduces the effort required to pull a mass by factor of 2 × number of movable pulleys. Consider a simple example of single fixed and movable pulley.

In case I of fixed pulley the effort will be same as of load being lifted as tension in rope will be same across pulley, hence mechanical advantage will be 1.

F

effort

=F

load

In case II of movable pulley the effort will be half of that load being lifted as the forces on mass less pulley should balance, mechanical advantage will be 2.

2F

effort

=F

load

⇒F

effort

=F

load

/2