1. By: Adhithi Raghavan Period 1

2.  Force - the push or pull on an object.  Work- when you exert a force on an object to make the object move a distance Work = Force x Distance  If the object weighs more than the force you can exert, you use a machine.  Machine- a device that allows you to work in an easier way.

3.  Lever – a rigid rod that is free to rotate around a fixed pivot point  The lever makes the work easier by increasing the amount of force exerted on the object.  Fulcrum- the fixed pivot point that a lever rotates around  Hand near the fulcrum- less force  Hand farther away from the fulcrum- more force  Effort Force- the force you exert on a lever  Effort Distance- the distance you push down  Resistance Force- the force that a lever exerts on an object  Resistance Distance- the distance the lever pushes up on an object

4. Mechanical Advantage  A lever’s mechanical advantage is the number of times a lever increases a force exerted on it.  Mechanical advantage is given in the ratio: Mechanical Advantage = Resistance Force Effort Force  Mechanical advantage measures the amount of force that is exerted by the lever. Law of the Lever  The law of the lever states that for the lever to be balance, the effort force times the effort arm must be equal to the resistance force times the resistance arm.  Example:  If you balanced a spoon on your finger, the spoon is the lever, and the finger acts as the fulcrum. In order to balance the spoon, the spoon as to be near the fulcrum.  Effort Arm: the distance from the fulcrum the effort force.  Resistance Arm: the distance from the fulcrum to the resistance force Effort Arm Resistance Arm

5.  3 different classes of levers.  First-Class Lever:  The fulcrum is between the effort force and resistance force. =Resistance Force = Effort Force = Fulcrum  Second-Class Lever:  The resistance force is between the effort force and the fulcrum.  Third-Class Lever:  The effort force is between the resistance force and fulcrum.

6.  The joints in the body act as fulcrums.  The bones act as levers, and the muscles provide the force.  The thigh, wrist, and shoulder joints act as fulcrums for third- class levers.  In the three types of levers the effort force is applied at the point where a muscle attaches to the bone.  The bone is the lever, and the resistance force is the force exerted by the bone.