Answer:
<h2>
The magnitude of force F is 18N</h2>
Explanation:
The magnitude of the force in the set up can be solved for using the principle of moment. According to the principle, the sum of clockwise moment is equal to the sum of anticlockwise moments.
Moment = Force * perpendicular distance
Clockwise moments;
The force that acts clockwise is the unknown Force F and 4N force. If the beam rests on a pivot 60 cm from end X and a Force F acts on the beam 80 cm from end X, the perpendicular distance of the force F from the pivot is 80-60 = 20cm and the perpendicular distance of the 4N force from the pivot is 60-50 = 10cm
Moment of force F about the pivot = F * 20
Moment of 4N force about the pivot = 4*10 = 40Nm
Sum of clockwise moment = 40+20F...(1)
Anticlockwise moment;
The 8N will act anticlockwisely about the pivot.
The distance between the 8N force and the pivot is 60-10 = 50cm
Moment of the 8N force = 8*50
=400Nm...(1)
Equating 1 and 2 we have;
40+20F = 400
20F = 400-40
20F = 360
F = 18N
The magnitude of force F is 18N
