Question

A 90.0 gram mass is 75 centimeters from the pivot point on a balance scale. What mass must be placed 45

centimeters from the pivot to create rotational equilibrium?

Answer 1

Step-by-step explanation:

Given:

m₁ = 90.0 gram = 0.090 kg

L₁ = 75 cm = 0.75 m

L₂ = 45 cm = 0.45 m

__________________

m₂ - ?

Lever balance (rule of moments):

M₁ = M₂

F₁·L₁ = F₂·L₂

m₁·g·L₁ = m₂·g·L₂

m₁·L₁ = m₂·L₂

Mass:

m₂ = m₁·L₁ / L₂

m₂ = 0.090·0.75 / 0.45 = 0.150 kg or 150 gram