1.5 Effects of Forces
Moments & Balance Beam Lab
Place weights of varying masses at different positions on a pivoted see-saw. Calculate anticlockwise and clockwise moments to achieve balance.
Virtual Viewport
Anticlockwise (Left) Moment
147.2 N·m
Clockwise (Right) Moment
117.7 N·m
Active Sliders
m₁Left Mass5kg
110
Mass placed on left see-saw side.
d₁Left Distance3.00m
15
Distance of left mass from center pivot.
m₂Right Mass3kg
110
Mass placed on right see-saw side.
d₂Right Distance4.00m
15
Distance of right mass from center pivot.
Syllabus Objectives
- Define moment of a force as force times perpendicular distance (F × d)
- State and apply the principle of moments for a system in equilibrium
- Calculate unknown force or distance on a balance beam.
Mathematical Equations
Moment of Force
M = F × d
Equilibrium Condition
M_{anticlockwise} = M_{clockwise}
Inquiry Guide Sheet
1
Place a 4kg mass 3m to the left of the pivot. Calculate the anticlockwise moment.
2
Predict where you must place a 6kg mass on the right to balance the see-saw. Verify with sliders.
3
Sum the moments on each side and observe how the beam rotates when moments are unequal.