Question

The boy applying the input force moves so that he is 1.5m from the fulcrum. the seesaw applies an output force to the other boy who is 2m from the fulcrum. what is the new ideal mechanical advantage?

Answer 1

Mechanical advantage is defined as the ratio of output force and input force

so we can say it is

$\eta = \frac{F_{out}}{F_{in}}$

now here we know that on a see saw torque is balanced

so we can say

$F_1r_1 = F_2r_2$

so here it is given as

$F_{in}\times 1.5 = F_{out} \times 2$

so here we can say

$\eta = \frac{F_{out}}{F_{in}} = 0.75$

so mechanical advantage will be 0.75