Movement

Mass is a measure of an object's inertial force, or how it resists motion, and the amount of matter in it. Weight is the measure of gravity's pulling on objects. Mass is independent of gravity, so the mass of an object will be the same on both earth and the moon. Because weight is dependent upon gravity, and the earth has a greater force of gravity than the moon, and object on earth will weigh more than it will on the moon.

A. The energy an object has due to its motion

First class levers have the fulcrum between the load and effort. This distinguishes first class levers from second and third class levers, where the load and the effort are both on one side of the fulcrum.

C. Force

A. First class lever

B.Tendons

Levers are tools that allow a small effort to move significantly larger loads. This apparent magnification of the force applied to a lever, and the force resulting from it, is called its mechanical advantage.

C. Third class lever

According to newtons first law, the law of inertia, an objects velocity will not change unless it is acted upon by an outside force. This means that objects at rest tend to stay at rest, and objects in motion tend to stay in motion.

The seesaw is a long lever arm with the load at one end, the effort at the opposite end, and the fulcrum in the center. With both the second and third class levers, however, the fulcrum is at one end of the lever and both the load and effort or on one side of the fulcrum. The seesaw is closest in arrangement to a first class lever because it is the only class of lever with the fulcrum between the load and effort.