In the diagram above, MN is perpendicular to ON and MP. What is the difference between the moment about N of the force of 20 Newtons applied along MP and its moment about O?
Attached Figure / Diagram
A
Zero
B
0.2N.m
C
0.4N.m
D
0.8N.m
E
0.6N.m
Verified Correct Answer: A.
Physical Principles & Numerical Solution
Given: Force \( P = 20 \, \text{N} \), Distance \( MN = 0.4 \, \text{m} \)
Moment About Point N: \(\text{Moment}_N = P \times MN = 20 \, \text{N} \times 0.4 \, \text{m} = 8 \, \text{Nm}\)
Moment About Point O: \(\text{Distance from O} = 0.5 \times \cos(36.87^\circ) \approx 0.4 \, \text{m}\)
\(\text{Moment}_O = P \times \text{Distance from O} = 20 \, \text{N} \times 0.4 \, \text{m} = 8 \, \text{Nm}\)
Difference Between Moments: \(\text{Difference} = \text{Moment}_N - \text{Moment}_O = 8 \, \text{Nm} - 8 \, \text{Nm} = 0 \, \text{Nm}\)
Source: Myschool Past Questions Archive (Record #41613)