Kali ini kita akan membahas tentang pesawat sederhana (simple machine), tapi pembahasannya dalam bahasa inggris saja ya...
A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that provide mechanical advantage (also called leverage)
Classification of Simple Machine
1.Levers
Levers are used to lift heavy weights with the least amount of effort. The fulcrum is the place where the rod pivots or rotate. The load is the scientific name for weight. And the effort is quite simply the amount of effort used to push down or move the weight.
There are three classes of lever.
a. Lever class one
First-class levers have the fulcrum placed between the load and the effort, as in the seesaw, crowbar, and balance scale.
crowbar
balance scale
b. Lever class two
Second-class levers have the load between the effort and the fulcrum. A wheelbarrow is a second-class lever. The wheel’s axle is the fulcrum, the handles take the effort, and the load is placed between them. The effort always travels a greater distance and is less than the load.
ex : wheel’s axle
c. Lever class three
Third-class levers have the effort placed between the load and the fulcrum. The effort always travels a shorter distance and must be greater than the load. A hammer acts as a third-class lever when it is used to drive in a nail: the fulcrum is the wrist, the effort is applied through the hand, and the load is the resistance of the wood. Another example of a third-class lever is the human forearm: the fulcrum is the elbow, the effort is applied by the biceps muscle, and the load is in the hand.
ex : hammer
2. Inclined Plane
The Inclined Plane is a sloping surface (like a ramp) that can be used to alter the effort and distance involved in doing work, such as lifting loads. The tradeoff is that an object must be moved a longer distance than if it was lifted straight up, but less force is needed. Examples include staircases, ramps, and the bottom of a bathtub.
Mechanical advantage of inclined plane
3. Pulley
Pulleys can be used to simply change the direction of an applied force or to provide a force/distance tradeoff in addition to a directional change.
Source:
http://www.ohio.edu
http://www.technologystudent.com
http://www.clear.rice.edu
ex : wheel’s axle
c. Lever class three
Third-class levers have the effort placed between the load and the fulcrum. The effort always travels a shorter distance and must be greater than the load. A hammer acts as a third-class lever when it is used to drive in a nail: the fulcrum is the wrist, the effort is applied through the hand, and the load is the resistance of the wood. Another example of a third-class lever is the human forearm: the fulcrum is the elbow, the effort is applied by the biceps muscle, and the load is in the hand.
ex : hammer
2. Inclined Plane
The Inclined Plane is a sloping surface (like a ramp) that can be used to alter the effort and distance involved in doing work, such as lifting loads. The tradeoff is that an object must be moved a longer distance than if it was lifted straight up, but less force is needed. Examples include staircases, ramps, and the bottom of a bathtub.
Mechanical advantage of inclined plane
3. Pulley
Pulleys can be used to simply change the direction of an applied force or to provide a force/distance tradeoff in addition to a directional change.
Source:
http://www.ohio.edu
http://www.technologystudent.com
http://www.clear.rice.edu
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