Simple Machines & Their Mechanical Advantages

Wedge It is used to push an object(s) apart. It is made up of two inclined planes. These planes meet and form a sharp edge. The edge can split things apart.

Wedge

Inclined Plane It is a flat surface that is higher on one end. You can use this machine to move an object to a lower or higher place Makes the work of moving things easier. You would need less energy and force to move objects with it.

Inclined Plane

Lever It is a board or bar that rests on a turning point. This turning point is called the fulcrum. An object that a lever moves is called the load. The closer the object is to the fulcrum, the easier it is to move.

Lever

Pulley It is made up of a wheel and a rope. The rope fits on the groove of the wheel. One part of the rope is attached to the load. When you pull on one side of the it, the wheel turns and the load will move. This device allows you to move loads up, down, or sideways.

Pulley

Screw It is made from another simple machine. It is actually an inclined plane that winds around itself. It has ridges and is not smooth like a nail. Some of them are used to lower and raise things. They are also used to hold objects together.

Screw

Wheel and Axle It has an axle which is a rod that goes through the wheel. The axle lets the wheel turn. Together, these devices allow things to be moved easily from place to place.

Wheel and Axle

Kinds of Lever There are three different kinds of levers. The location of the fulcrum, resistance arm, and effort arm is what makes them different

Kinds of Lever All levers have two arms, called the effort arm and the resistance arm.

Kinds of Lever The effort arm is the distance from the fulcrum and the effort.

Kinds of Lever The resistance arm is the distance from the fulcrum and the resistance.

A First-Class Lever The fulcrum is located between the force and resistance.

A Second-Class Lever Is set-up so that the resistance is between the force and fulcrum

The force is between the resistance and the fulcrum. A Third-Class Lever

Lever Equation This equation can be used to find unknowns: Effort Force X Effort Arm Length = Resistance Force X Resistance Arm Length

Finding Lever Unknowns How much force is needed to move a rock that weighs 100 pounds using a lever with an arm length of four feet and a resistance arm length of one foot?

Finding Lever Unknowns How much force is needed to move a rock that weighs 100 pounds using a lever with an arm length of four feet and a resistance arm length of one foot? Effort Force X Effort Arm Length = Resistance Force X Resistance Arm Length

Finding Lever Unknowns How much force is needed to move a rock that weighs 100 pounds using a lever with an arm length of four feet and a resistance arm length of one foot? Effort Force X 4 ft. = Resistance Force X Resistance Arm Length

Finding Lever Unknowns How much force is needed to move a rock that weighs 100 pounds using a lever with an arm length of four feet and a resistance arm length of one foot? Effort Force X 4 ft. = 100 lbs. X Resistance Arm Length

Finding Lever Unknowns How much force is needed to move a rock that weighs 100 pounds using a lever with an arm length of four feet and a resistance arm length of one foot? Effort Force X 4 ft. = 100 lbs. X 1 ft.

Finding Lever Unknowns How much force is needed to move a rock that weighs 100 pounds using a lever with an arm length of four feet and a resistance arm length of one foot? Effort Force X 4 ft. = 100 lbs. per ft.

Finding Lever Unknowns How much force is needed to move a rock that weighs 100 pounds using a lever with an arm length of four feet and a resistance arm length of one foot? Effort Force = 100 lbs. per ft. / 4 ft.

Finding Lever Unknowns How much force is needed to move a rock that weighs 100 pounds using a lever with an arm length of four feet and a resistance arm length of one foot? Effort Force = 25 lbs.

A Lever’s Mechanical Advantage The mechanical advantage (M.A.) of a lever is determined by dividing the length of the effort arm by the length of the resistance arm. M.A. = Effort Arm / Resistance Arm

A Lever’s Mechanical Advantage What is the mechanical advantage for a lever with an effort arm of 6 meters and a resistance arm of 1.5 meters?

A Lever’s Mechanical Advantage What is the mechanical advantage for a lever with an effort arm of 6 meters and a resistance arm of 1.5 meters? M.A. = Effort Arm / Resistance Arm

A Lever’s Mechanical Advantage What is the mechanical advantage for a lever with an effort arm of 6 meters and a resistance arm of 1.5 meters? M.A. = 6 m / Resistance Arm

A Lever’s Mechanical Advantage What is the mechanical advantage for a lever with an effort arm of 6 meters and a resistance arm of 1.5 meters? M.A. = 6 m / 1.5 m

A Lever’s Mechanical Advantage What is the mechanical advantage for a lever with an effort arm of 6 meters and a resistance arm of 1.5 meters? M.A. = 9 The mechanical advantage of this lever is 9. This means that the lever multiplied the effort 9 times.

A Wheel and Axle’s Mechanical Advantage The mechanical advantage (M.A.) for a wheel and axle is determined by dividing the diameter of the wheel

A Wheel and Axle’s Mechanical Advantage The mechanical advantage (M.A.) for a wheel and axle is determined by dividing the diameter of the wheel by the diameter of the axle.

A Wheel and Axle’s Mechanical Advantage What is the mechanical advantage of the wheel that has a diameter of 25 cm and an axle with a diameter of 2 cm?

A Wheel and Axle’s Mechanical Advantage mechanical advantage (M.A.) = diameter of the wheel / the diameter of the axle

A Wheel and Axle’s Mechanical Advantage mechanical advantage (M.A.) = 25 cm / the diameter of the axle

A Wheel and Axle’s Mechanical Advantage mechanical advantage (M.A.) = 25 cm / 2 cm

A Wheel and Axle’s Mechanical Advantage mechanical advantage (M.A.) = 12.5 The mechanical advantage of this wheel with this axle is 12.5.

Mechanical Advantage Of A Fixed Pulley The mechanical advantage (M.A.) of a moveable pulley is determined by the number of supporting ropes. The mechanical advantage (M.A.) of a fixed pulley with one supporting strand is 1.

Mechanical Advantage Of A Fixed Pulley The mechanical advantage (M.A.) of a moveable pulley is determined by the number of supporting ropes. One supporting strand. The effort needed to lift a 10 gram weight is 10 grams (10/1).

Mechanical Advantage Of A Moveable Pulley The mechanical advantage (M.A.) of a moveable pulley is determined by the number of supporting ropes. The mechanical advantage (M.A.) of a moveable pulley with two supporting strand is 2.

Mechanical Advantage Of A Moveable Pulley The mechanical advantage (M.A.) of a moveable pulley is determined by the number of supporting ropes. Two supporting strands The effort need to lift a 10 gram weight is 5 grams (10/2).

Inclined Plane

Mechanical Advantage of An Inclined Plane The mechanical advantage (M.A.) of an inclined plane is the length of the incline divided by its height.

Mechanical Advantage of An Inclined Plane A man is using an 8 foot board to slide things into the back of his truck. The truck is 2.5 feet from the ground. What is the mechanical advantage of this incline?

Mechanical Advantage of An Inclined Plane mechanical advantage (M.A.) of an inclined plane = the length of the incline / by its height

Mechanical Advantage of An Inclined Plane mechanical advantage (M.A.) of an inclined plane = 8 ft. / by its height

Mechanical Advantage of An Inclined Plane mechanical advantage (M.A.) of an inclined plane = 8 ft. / 2.5 ft.

Mechanical Advantage of An Inclined Plane mechanical advantage (M.A.) of an inclined plane = 3.2 This means the effort is multiplied by 3.2 when using this inclined plane.

Wedge

Screw This simple demonstration shows how a screw is actually an inclined plane. Materials Pencil Paper Colored felt tip marker Scissors

Screw Procedure 1. Cut a right triangle from the paper. The dimensions should be about 5 inches, by 9 inches, by 10.3 inches. 2. Use the felt tip marker to color the longest edge (10.3 inches) of the triangle. 3. Position the shortest side (5 inches) of the triangle along the side of the pencil and then evenly wrap the paper around the pencil by rolling the pencil.

Screw

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