At the ends of the lever, forces of 4N and 20N act. The length of the arm is 1.5 m. Where is the fulcrum if the arm is in balance?

Given:
F1 = 20 N.
F2 = 4 N.
l = 1.5 m.
According to the lever balance rule:
F1 / F2 = l2 / l1, F1 – force acting on the shoulder l1; F2 is the force acting on the arm l2, l1, l2 are the arms of the lever (l = l1 + l2).
F1 / F2 = l2 / l1 = 20/4 = 5.
The length of the l2 shoulder is 5 times longer than the l1 shoulder. Therefore: l2 = 5 * l1.
l = l2 + l1 = 5 * l1 + l1 = 6 * l1 = 1.5 m.
l1 = 1.5 / 6 = 0.25 m.
l2 = 5 * l1 = 5 * 0.25 = 1.25 m.
Answer: The fulcrum is 0.25 m from the end of the arm with a force of 20 N and at a distance of 1.25 m from the end with a force of 5 N.