Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 1, 2025
*To show the Action of Levers.*—With a light but stiff wooden bar, a spring balance, and a wedge-shaped fulcrum, show: 1. The position of the weight, the fulcrum, and the power in the different classes of levers, and also the weight-arm and the power-arm in each case. The direction moved by the power and the weight respectively in the use of the different classes of levers.
In the second class the weight is between the fulcrum and the power. In the third class the power is between the fulcrum and the weight. I.* Two levers of first class showing fulcrums in different positions. II. Lever of second class. III. Lever of third class. F. Fulcrum. P. Power. W. Weight. a. Power-arm. b. Weight-arm.
Show that the force required to support the weight increases proportionally as the weight-arm and as the distance through which the weight may be moved by the lever. Apply to the action of the biceps muscle in lifting weights on the forearm. *A Study of the Action of the Biceps Muscle.*—Place the fingers upon the tendon of the biceps where it connects with the radius of the forearm.
That when the power-arm and weight-arm are equal, the power equals the weight and moves through the same distance. That when the power-arm is longer than the weight-arm, the weight is greater, but moves through a shorter distance than the power. That when the weight-arm is longer than the power-arm, the power is greater and moves through a shorter distance than the weight.
If other positions are tried, it is found that the power exerted in each case is as many times greater than the weight as the weight-arm is times longer than the power-arm. Applying this principle to the levers of the body, it is seen that the gain in motion is at the expense of muscular force, or, as we say, muscular force is exchanged for motion.
Word Of The Day
Others Looking