LEVERS In technology. The wedge and screw are a type of inclined plane. The wedge is designed for splitting durable objects, such as logs. It is also driven into the cracks between the parts in order to create a greater pressure force of one part on another and thereby increase the static friction force between them, which will ensure their reliable adhesion. Given the enormous forces applied to the wedge, it must be very strong, made of the hardest material. The “piercing tools” of many animals and plants - claws, horns, teeth and spines - are shaped like a wedge (a modified inclined plane); The pointed shape of the head of fast-moving fish is also similar to the wedge. Many of these wedges have very smooth hard surfaces, which gives them great sharpness.
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“Levers in everyday life” - Simple mechanisms. Levers in everyday life. Types of lever: block and gate. Inclined plane. Gate block lever. Inclined plane wedge screw. What can a person use to do work? Lever balance. Mechanical work. Levers in technology and everyday life: a press with a lever. During the construction of the pyramids in Ancient Egypt.
“Levers” - Scissors for cutting metal. Axis of rotation. Levers in everyday life, technology and nature. In which case is it easier to carry the load? Gate. Support point. Wheelbarrow.
“Lever mechanism” - Lever. What type of lever is in the picture? Which of the proposed mechanisms uses a lever? Lever arm - solid, capable of rotating around a fixed support. Simple mechanisms. Taking the length of 1 cell as 1 cm, determine numeric value each shoulder. Special levers. Construct the arms of the forces applied to the lever.
“Levers in nature and technology” - Lever mechanisms. Levers in wildlife and technology. Movable bones. Levers in arthropods. Archimedes. Levers in technology. Levers in bivalves. Dorsal fin spines. Levers in living nature. Lever mechanisms of the skeleton.
"Lever" - Sweeper. Load: Mine laboratory setup. The adults explained to me that I used the door as a lever. How do people use leverage? Lever of the second type. Converting distance using a lever. Load application point. Leverage calculator. Force application point. What is a lever? I came up with my own uses for leverage.
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School p. Third decisive
Report
discipline: "Physics"
on the topic of:" "
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student_7__ class
Tolokonnikov Vladimir
Checked by: Oleynikov Nikolay
Viktorovich
__________________________
Levers in nature, everyday life and technology
The lever is one of the most common and simple types mechanisms in the world, present both in nature and in man-made world created by man.
The human body is like a lever
For example, the skeleton and musculoskeletal system of a person or any animal consists of tens and hundreds of levers. Let's take a look at the elbow joint. The radius and humerus are connected together by cartilage, and the biceps and triceps muscles are also attached to them. So we get the simplest lever mechanisms.
If you hold a 3 kg dumbbell in your hand, how much force does your muscle develop? The junction of bone and muscle is divided by bone in a ratio of 1 to 8, therefore, the muscle develops a force of 24 kg! It turns out that we are stronger than ourselves. But the lever system of our skeleton does not allow us to fully use our strength.
A good example more successful application of the advantages of leverage in the musculoskeletal system of the body reverse hind knees in many animals (all types of cats, horses, etc.).
Their bones are longer than ours, and the special structure of their hind legs allows them to use the power of their muscles much more efficiently. Yes, undoubtedly, their muscles are much stronger than ours, but their weight is an order of magnitude greater.
The average horse weighs about 450 kg, and can easily jump to a height of about two meters. You and I, in order to perform such a jump, need to be masters of sports in high jumping, although we weigh 8-9 times less than a horse.
Since we remembered about high jumps, let's consider the options for using the lever that were invented by man. High vaulta very clear example.
Using a lever about three meters long (the pole for high jumps is about five meters long, therefore, the long arm of the lever, starting at the bend of the pole at the moment of the jump, is about three meters) and the correct application of force, the athlete soars to a dizzying height of up to six meters.
Lever in everyday life
Levers are also common in everyday life. It would be much more difficult for you to open a tightly screwed water tap, if it did not have a 3-5 cm handle, which is a small but very effective lever.
The same applies to a wrench that you use to loosen or tighten a bolt or nut. The longer the wrench, the easier it will be for you to unscrew this nut, or vice versa, the tighter you can tighten it.
When working with particularly large and heavy bolts and nuts, for example, when repairing various mechanisms, cars, machine tools, use spanners with a handle up to a meter.
Another striking example of leverage in Everyday life the most ordinary door. Try opening the door by pushing it near the hinges. The door will give in very hard. But the farther the point of force application is located from the door hinges, the easier it will be for you to open the door.
Levers in technology
Naturally, levers are also ubiquitous in technology.The most obvious examplegear shift lever in a car. The short arm of the lever is the part that you see in the cabin.
The long arm of the lever is hidden under the bottom of the car, and is approximately twice as long as the short one. When you move the lever from one position to another, a long arm in the gearbox shifts the corresponding mechanisms.
Here you can also very clearly see how the length of the lever arm, the range of its stroke and the force required to shift it relate to each other.
For example, in sports cars, to change gears faster, the lever is usually installed short, and its travel range is also short.
However, in this case the driver needs to make more effort to change gear. On the contrary, in heavy vehicles, where the mechanisms themselves are heavier, the lever is made longer, and its range of travel is also longer than in a passenger car.
Thus, we can be convinced that the lever mechanism is very widespread both in nature and in our everyday life, and in various mechanisms.
“Levers in nature and technology” - Levers in technology. Lever mechanisms. Archimedes. Levers in living nature. Dorsal fin spines. Levers in arthropods. Levers in wildlife and technology. Movable bones. Levers in bivalves. Lever mechanisms of the skeleton.
“Levers” - Wheelbarrow. Scissors for cutting metal. Support point. In which case is it easier to carry the load? Gate. Axis of rotation. Levers in everyday life, technology and nature.
“Leverage” - How else can you use leverage? Cargo. Not all classmates can apply their knowledge about levers. Archimedes, connecting the concepts of force, load and shoulder. Using a computer program, calculating levers is more convenient and faster. The adults explained to me that I used the door as a lever. Lever of the second type. What other properties does a lever have?
“Simple mechanisms - lever” - Name of the list. Lever device. Using leverage. Which lever will be in equilibrium? Mechanisms. Simple mechanisms. Scissors. Lever equilibrium condition. Two types of levers. Consolidation. Shoulder. Why door handle not attached to the middle of the door. Adaptations. Lever arm.
“Block” - Application of the law of lever equilibrium to a block. " Golden Rule» mechanics. When they gain 2 times in strength, they lose 2 times along the way. Equality of work when using a moving block. Fixed block. Combination of blocks. Equality of work when using a lever. There is no gain in work when using leverage.
“Levers in everyday life” - Types of lever: block and gate. Inclined plane wedge screw. Lever balance. Mechanical work. A=fs. Wedge and screw. Gate block lever. Levers in technology and everyday life: single-cup lever scales. Levers in technology and everyday life: a press with a lever. Simple mechanisms. Lever arm. What can a person use to do work?
School p. Third decisive
Report
discipline: "Physics"
on the topic of:"»
Completed:
student_7__ class
Tolokonnikov Vladimir
Checked by: Oleynikov Nikolay
Viktorovich
__________________________
Levers in nature, everyday life and technology
The lever is one of the most common and simple types of mechanisms in the world, present both in nature and in the man-made world created by man.
The human body is like a lever
For example, the skeleton and musculoskeletal system of a person or any animal consists of tens and hundreds of levers. Let's take a look at the elbow joint. The radius and humerus are connected together by cartilage, and the biceps and triceps muscles are also attached to them. So we get the simplest lever mechanisms.
If you hold a 3 kg dumbbell in your hand, how much force does your muscle develop? The junction of bone and muscle is divided by bone in a ratio of 1 to 8, therefore, the muscle develops a force of 24 kg! It turns out that we are stronger than ourselves. But the lever system of our skeleton does not allow us to fully use our strength.
A clear example of a more successful application of the advantages of leverage in the musculoskeletal system of the body is the reverse hind knees in many animals (all types of cats, horses, etc.).
Their bones are longer than ours, and the special structure of their hind legs allows them to use the power of their muscles much more efficiently. Yes, undoubtedly, their muscles are much stronger than ours, but their weight is an order of magnitude greater.
The average horse weighs about 450 kg, and can easily jump to a height of about two meters. You and I, in order to perform such a jump, need to be masters of sports in high jumping, although we weigh 8-9 times less than a horse.
Since we remembered about high jumps, let's consider the options for using the lever that were invented by man. High vaulta very clear example.
Using a lever about three meters long (the pole for high jumps is about five meters long, therefore, the long arm of the lever, starting at the bend of the pole at the moment of the jump, is about three meters) and the correct application of force, the athlete soars to a dizzying height of up to six meters.
Lever in everyday life
Levers are also common in everyday life. It would be much more difficult for you to open a tightly screwed water tap if it did not have a 3-5 cm handle, which is a small but very effective lever.
The same applies to a wrench that you use to loosen or tighten a bolt or nut. The longer the wrench, the easier it will be for you to unscrew this nut, or vice versa, the tighter you can tighten it.
When working with particularly large and heavy bolts and nuts, for example, when repairing various mechanisms, cars, machine tools, use wrenches with a handle up to a meter.
Another striking example of a lever in everyday life is the most ordinary door. Try opening the door by pushing it near the hinges. The door will give in very hard. But the farther the point of force application is located from the door hinges, the easier it will be for you to open the door.
Levers in technology
Naturally, levers are also ubiquitous in technology.The most obvious example gear shift lever in a car. The short arm of the lever is the part that you see in the cabin.
The long arm of the lever is hidden under the bottom of the car, and is approximately twice as long as the short one. When you move the lever from one position to another, a long arm in the gearbox shifts the corresponding mechanisms.
Here you can also very clearly see how the length of the lever arm, the range of its stroke and the force required to shift it relate to each other.
For example, in sports cars, to change gears faster, the lever is usually installed short, and its travel range is also short.
However, in this case the driver needs to make more effort to change gear. On the contrary, in heavy vehicles, where the mechanisms themselves are heavier, the lever is made longer, and its range of travel is also longer than in a passenger car.
Thus, we can be convinced that the lever mechanism is very widespread both in nature and in our everyday life, and in various mechanisms.
- 1. Levers in technology, everyday life and nature. Since time immemorial, people have used various devices to perform mechanical work. Using levers 3 thousand. years ago, during the construction of the Cheops pyramid in Ancient Egypt, slabs weighing 2.5 tons were moved and raised to a height of up to 147 meters. Simple mechanisms are devices used to convert force. TO simple mechanisms include: lever and its varieties - block, gate; inclined plane and its varieties - wedge, screw. In most cases, simple mechanisms are used to obtain a gain in strength, i.e. e.increase the force acting on the body several times.
- 2. Block is one of the types of lever. In everyday life it is used as a fixed block that changes the direction of force, for example, to lift weights to a height; so and a movable block, to obtain a gain in strength.
- 3. Lever A lever is a rigid body that can rotate around a fixed support. The shortest distance between the fulcrum and the straight line along which the force acts on the lever is called the arm of force. The lever is in equilibrium when the forces acting on it are inversely proportional to the arms of these forces. The rule of leverage was established by Archimedes around 287-212. BC e. From this rule it follows that a smaller force can balance a larger force with the help of a lever. In this case, the shoulder of lesser strength should be longer than the shoulder of greater strength.
- 4. Lever in technology, nature, everyday life The rule of leverage underlies the action of various types of devices and tools used in technology and everyday life where a gain in force or path is required. Examples include scissors, wire cutters, and metal cutting shears. Levers various types Many machines have: the handle of a sewing machine, the pedals or handbrake of a bicycle, the keys of a piano - all these are examples of levers. Scales are also an example of a lever. Levers are also found in different parts bodies of animals and humans. These are limbs, jaws. Many levers can be identified in the body of insects, birds, and the structure of plants.
- 5. Historical reference The great mathematician, mechanic and engineer of antiquity Archimedes was born in 287 BC. e. (presumably) in Syracuse, a rich trading city in Sicily. His father was the astronomer Phidias, who instilled in his son a love of mathematics, mechanics and astronomy from childhood. Already during Archimedes’s lifetime, legends were created around his name, the reason for which was his amazing inventions, which had a stunning effect on his contemporaries. There is a well-known story about how Archimedes was able to determine whether the crown of King Nero was made of pure gold or whether the jeweler mixed a significant amount of silver into it. Specific gravity gold was known, but the difficulty was to accurately determine the volume of the crown: after all, it had an irregular shape! Archimedes pondered this problem all the time. One day he was taking a bath, and then a brilliant idea occurred to him: by immersing the crown in water, you can determine its volume by measuring the volume of water displaced by it.
- 6. Legend. Another legend says that the luxurious ship Syrokosia, built by Hyperon as a gift to the Egyptian king Ptolemy, could not be launched. Archimedes built a system of blocks (pulley hoist), with the help of which he was able to do this work with one movement of his hand. This incident or Archimedes' reflections on the principle of the lever served as the reason for his winged words: “Give me a fulcrum, and I will move the Earth.” Archimedes also became famous for other mechanical structures. The endless, or Archimedean, screw he invented for scooping out water is still used in Egypt. Archimedes built a planetarium, or “celestial sphere,” during the movement of which it was possible to observe the movement of the five planets, the rising of the Sun and the Moon, the phases and eclipses of the Moon, and the disappearance of both bodies beyond the horizon. Archimedes' ideas were almost two millennia ahead of their time.
- 7. Moment of force. The product of the modulus of the force rotating the body and its shoulder is called the moment of force. M=F*l The unit of measurement for moment of force is 1 newton*meter. From here we can formulate another rule for the equilibrium of a lever: a lever is in equilibrium under the action of two forces if the moment of the force rotating it clockwise is equal to the moment of the force rotating it counterclockwise. This rule is called the rule of moments. The moment of force characterizes the action of a force and shows that it depends simultaneously on both the modulus of the force and its leverage. Indeed, the easier it is to turn the door, the further away from the axis of rotation the force acting on it is applied; The easier it is to lift a bucket from the well, the longer the gate handle, etc.
- 8. Moment of force It is easier to carry a load when the moment of force is smallest, that is, with the same load, having a smaller shoulder, the moment of force will be smaller. It is easier for the first boy to carry the load.1 2
- 9. Lever scales The action of lever scales is based on the principle of the lever: a) automobile, b) educational, c) medical, d) store. abc d
- 10. The rule of leverage in everyday life Scissors are a lever whose rotation axis passes through a screw connecting both halves of the scissors. The acting force F1 is the muscular force of the hand of the person squeezing the scissors. Counter-acting force F2 is the resistance force of the material that the scissors cut. Depending on the purpose of the scissors, their design is different: a) for cutting material, the handles are shorter than the blades, b) for cutting metal, the handles are longer than the blades, because resistance there is more metal in) with wire cutters there is an even greater difference between the length of the handles and the cutting part, designed for cutting wire.abv
- 11. Gain in strength Using the rule of leverage, a worker carries a larger load on a cart than he would carry it in his hands.
- 12. Levers in nature Levers are found in different parts of the body of animals and humans: a) the human hand bent at the elbow at a right angle holds the ball, in this case the muscular force is equal to the weight of the ball, the elbow is the support, the radius is the shoulder of the lever; b) a person presses the pedal with his foot, depending on the position of the foot on the pedal, i.e. The fulcrum points can be pressed on the pedal with different amounts of force.