A metre rule is pivoted at its mid-point with a vertical force of 10N hanging from the distance 30cm from the mid-point. At what distance must a 15N force hang to balance the ruler horizontally?
A
30cm
B
10cm
C
20cm
D
25m
Verified Correct Answer: C.
Physical Principles & Numerical Solution
Clockwise moment = Anti-clockwise moment
10 x 30 = 15 x X
X = 20cm
Source: Myschool Past Questions Archive (Record #44698)