Question

if the effort is 200 gm the length of the effort arm is 40cm and the load is 400 gm, then find the length of the load arm using the principle of moments A) 10 cm B) 20 cm C) 40cm D) 80cm​

Answer 1

Given: The effort is 200 gm, the length of the effort arm is 40 cm and the load is 400 gm.

To find: The length of the load arm.

Solution:

• According to the principle of moments, a body is balanced when the product of the force and the perpendicular distance from the pivot of the load and the effort are equal.
• So, the length of the load arm can be calculated using the formula,

        $F_{e} * d_{e} = F_{l} * d_{l}$

• On replacing the terms with the values given in the question, the obtained equation is,

        $200 gm * 40 cm = 400 gm * d_{f}$

• On rearranging, the value of $d_{f}$ is found to be equal to,

        $d_{f} = \frac{200*40}{400}$

             $= 20 cm$

Therefore, the length of the load arm is 20 cm.