To restore equilibrium, the sum of the clockwise moments must be equal to the sum of the anticlockwise moments.
In this scenario, a force of 5 N is applied at a point 30 mm from end A. We need to calculate the force that must be applied at point B to restore equilibrium.
Here's how we can solve this:
1. Convert the distance from millimeters to meters:
30 mm = 30/1000 = 0.03 meters
2. Calculate the moment of the applied force at point A:
Moment at A = Force x Distance
Moment at A = 5 N x 0.03 m
Moment at A = 0.15 Nm
3. Since the meter rule is uniform, the center of gravity is at the midpoint. Therefore, the distance from point B to the center of gravity is equal to the distance from point A to the center of gravity, which is 0.5 meters.
4. Let's assume the force applied at point B is F.
The moment at B is given by:
Moment at B = Force at B x Distance
Moment at B = F x 0.5 m
Moment at B = 0.5F Nm
5. Set up the equation using the principle of moments:
Sum of clockwise moments = Sum of anticlockwise moments
0.15 Nm = 0.5F Nm
6. Solve for F:
0.5F = 0.15
F = 0.15 / 0.5
F = 0.3 N
Therefore, a force of 0.3 N must be applied at point B to restore equilibrium.