The length of one arm of the lever is 50 cm, the other is 10 cm. A force of 400 N acts on the larger arm.
The length of one arm of the lever is 50 cm, the other is 10 cm. A force of 400 N acts on the larger arm. What force must be applied to the smaller arm in order for the lever to be in balance?
L1 = 50 cm = 0.5 m.
L2 = 10 cm = 0.1 m.
F1 = 400 N.
F2 -?
When the lever is in equilibrium, the moments of forces that act from opposite sides of the lever are equal to each other: M1 = M2.
The moment of force M is called the product of the applied force F to the smallest distance from the application of force in the axis of rotation of the lever L, which is called the lever arm: M = F * L.
F1 * L1 = F2 * L2.
The force that should act on the smaller shoulder is determined by the formula: F2 = F1 * L1 / L2.
F2 = 400 N * 0.5 m / 0.1 m = 2000 N.
Answer: in order for the lever to be in balance, a force F2 = 2000 N must be applied to the smaller arm.