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In the experiment of studying the conditions of lever balance, we should balance the lever in the horizontal position first. What is the purpose of doing this?
Our physics teacher talked about this problem in order to measure the arm of force, and the teacher also emphasized it, absolutely right!
In the experiment of "studying the condition of lever balance", the equipment used includes lever with scale, iron frame, hook code, line and bar_________ Before the experiment, the lever should be balanced in position for the purpose of doing so; if the left end of the lever is on the high side during the experiment, or can be used to balance the lever in position for the purpose of doing so
In the experiment of "studying the condition of lever balance", the equipment used includes lever with scale, iron frame, hook code, line and spring dynamometer. Before the experiment, the lever should be balanced in the horizontal position, so as to facilitate the measurement of the arm of force and eliminate the influence of the dead weight of the lever on the lever balance, Then the balance nut at the right end can be adjusted to the left, or the balance nut at the left end can be adjusted to the left to balance the lever at the horizontal position. The purpose of this is to make the gravity of the lever pass through the fulcrum, so that the influence of the gravity of the lever on its rotation can be ignored, and the length of the arm of force can be measured or read out from the lever
What is the principle of light lever?
If the incident light is fixed, rotate the mirror for an angle A. then the reflected light will deflect 2A. If the reflected light is projected on a distant wall, the angle change of 2A will make the light spot move a large distance. However, the rotation distance of the mirror is generally small. This is a method for measuring small distance
|Mirror (rotation)
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|Contact (raise) | fulcrum
What are the similarities and differences between optical lever amplification method and mechanical lever principle
Optical lever and lever use the same principle and pure geometric relationship when the ratio of the end displacement and the cantilever length is equal; the force of the lever can be equal to the amount of work done, so that the product of the force and the displacement of the stressed point is equal, and then it is inversely proportional to the cantilever length
Suggestion: if you are a student, don't connect them
RELATED INFORMATIONS
- 1. What is the principle of light lever
- 2. How to explain the principle of balance with lever
- 3. The fulcrum of lever aocb is o. OA = CB = 40. OC = 30. OA vertical OC. OC vertical CB hangs 49 n object on A. B at least needs force to keep lever Ao horizontal. It has a direction of force A_________________ O l l l__________________ B C
- 4. In the experiment of exploring the mechanical efficiency of pulley block, what is the experimental principle
- 5. What are the rules of mechanical efficiency of pulley block? The more hook yards, the greater the mechanical efficiency
- 6. What factors are related to the mechanical efficiency of leverage
- 7. Why should the balance beam be made equal arm
- 8. What kind of lever is the balance? What principle does it use?
- 9. 1. Heating potassium permanganate to produce oxygen, the safe operation after the end of the experiment is first (), and then () 2. The function of ice water in water tank is () 3. It is proved that in the reverse catalysis test of hydrogen peroxide, 1.（ ） 2. Put manganese dioxide into large test tube and add 5ml hydrogen peroxide 3. After the reaction, filter, wash, dry and weigh the solid substance in the large test tube 4.（ ） After finishing this experiment, we need to prove the catalytic effect of manganese dioxide, and add an inquiry experiment: Inquiry () 4. The factors that affect the rate of chemical reaction may be ()
- 10. 1. Heat the white sugar in the pot until it turns black, and taste whether the black substance is sweet or not? 2. Take desiccant bag, add tap water and test its temperature change? 3. Take rust iron nail and white vinegar reaction 4. Take the polished nails and white vinegar to reflect 5. Take the outer metal skin of the battery and white vinegar to reflect 6. Add water to the battery contents, soak garlic, and test its germination, which is different from that of water 7. Take alkali surface and add white vinegar for reaction 8. Take different petal juice, add white vinegar and alkaline water to react
- 11. Students in a research study group used the following devices to explore the respiration of plants
- 12. Who is the source of oxygen in carbon dioxide produced by respiration Is it from oxygen
- 13. Animals and plants can inhale oxygen and exhale carbon dioxide. What is the function of organisms Now!
- 14. When plants breathe at night, they should absorb oxygen and release carbon dioxide as usual, but will they also absorb a little carbon dioxide to breathe? When plants breathe at night, they should absorb oxygen and release carbon dioxide as usual But will it also absorb a little carbon dioxide to breathe?
- 15. People and animals need to consume oxygen for breathing. Why can the volume fraction of oxygen in the air always maintain 21% 1. People and animals need to consume oxygen for breathing. Why can the volume fraction of oxygen in the air always maintain about 21%? 2. Can we draw a conclusion that nitrogen accounts for about 4 / 5 of the air from the burning experiment of red phosphorus in the bell jar? Why? 3. If there is water vapor in the air, will the content of water vapor change
- 16. In the article "carbon dioxide", green plants and carbon dioxide give out oxygen when they do (). Animals breathe in oxygen and exhale carbon dioxide. In this way, they keep ()
- 17. [chemistry] design an experiment to prove that respiration produces carbon dioxide
- 18. Please design a simple experiment to prove the existence of air in the mineral water bottle
- 19. The reason why the respiration of plants is not obvious under light is () A. Photosynthesis is strong, absorbing carbon dioxide B. respiration is not carried out under light C. photosynthesis inhibits respiration D. respiration is weakened under light
- 20. Why do you drop a drop of water on the slide for onion mounting in the first volume of the seventh grade of human education (what's the purpose of dropping water) but why do you drop normal saline when you do oral epithelium mounting? Why can't you drop water?