Answer:
d ₂ = 1.56 m : horizontal distance from where Susie sits to the axis of rotation.
Explanation:
M = F * d Formula (1)
F is the magnitude of said force (N)
d: distance to the axis of rotation
The direction of the moment is determined by the direction of rotation and can be assumed positive in a counterclockwise direction and negative in the clockwise direction.
Forces on the see-saw
W: Weight: in the vertical direction and down
W₁= m₁*g = 30 kg*9.8 m/s²= 294 N
W₂= m₂*g = 27 kg*9.8 m/s²= 264.6 N
Distances of the forces to the axis of rotation
d₁ = 1.4 m :distance from where W₁ is located to the axis of rotation
d₂ : distance from where W is located to the axis of rotation
Problem development
For static equilibrium the sum of moments around the axis of rotation is zero:
∑M =0
W₁*d₁ - W₂*d₂ = 0
W₁*d₁ = W₂*d₂
294*1.4 = 264.6*d₂
411.6= 264.6*d₂
d₂ =( 411.6) / (264.6)
d ₂= 1.56 m
