Two weights are balanced at the ends of the lever, the arms of which are 50 and 70 cm. Find the weight of the larger load if the force of pressure of the lever on the support is 72 N. The weight of the lever is neglected.
l1 = 50cm = 0.5m,
l2 = 70cm = 0.7m,
P = 72H;
Find: P1 -?
If the lever is in equilibrium, then according to the lever rule:
P1 * l1 = P2 * l2;
The pressure force of the lever without taking into account its weight is determined by the total weight of the loads:
P1 + P2 = P;
From the first equation we find:
P2 = P1 * (l1 / l2);
Substitute this expression into the second equation:
P1 + P1 * (l1 / l2) = P;
P1 = P / (1 + l1 / l2);
P1 = 72 / (1 + 0.5 / 0.7) = 72 * 0.7 / 1.2 = 42H.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.