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Push up is a common basic exercise. Xiaoming weighs 600N. He does 30 push ups in 1min. Every time he does it, his shoulder rises 50cm. Xiaoming's body is a lever, and O is a key If the area of each palm is 0.016 M & sup2;, calculate the pressure of both hands on the ground and the work done by Xiaoming in 3.1 Min. 4
This is a physical question, how to classify in the computer installation? The most exaggerated is the direct answer upstairs
Lever principle in human body
The human body's motion system is quite complex, but the most basic form of motion is that the skeleton rotates around the joint under the power provided by the muscles. For example, when the hand holds a tea cup, the forearm skeleton is equivalent to a lever, and the biceps brachii contraction provides power. What kind of lever is this?
(laborious or laborious, distance or distance?
It's hard work and saves distance, because the upper arm's force arm is shorter than the forearm's
How to draw the three levers of nail clippers
Lever in nail clipper: as shown in the figure, it is a schematic diagram of nail clipper, which is composed of three levers ABC, OBD and OED. ① analyze the force of lever ABC, and draw a schematic diagram: from the diagram, it can be seen that the power arm is larger than the resistance arm, so lever ABC is a labor-saving lever; ② when using nail clipper to cut nails
How to draw the lever diagram of nail clipper?
As shown in the figure:
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- 1. How to draw physical lever diagram
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- 3. Solving the labor saving principle of moving pulley
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- 5. Using the lever theorem, Give you a pen, a meter ruler, and some 50g weights to calculate the mass of the ruler
- 6. Archimedes's famous saying, as long as we give him a fulcrum on the earth, he can pry up the earth. What's the reason
- 7. Archimedes, a famous ancient Greek scholar, once said, "if you give me a lever and a fulcrum, I can pry the earth." Now let's make a hypothesis that C is the fulcrum, and the lever can rotate around C. We put the earth at point B. if the ratio of the power arm AC and the resistance arm BC of the lever is 5:1, and we want to lift the earth up 10 cm, how many m should we press the A end of the lever down?
- 8. When to use Archimedes theorem to calculate
- 9. Where is the insulating paint scraped away from the resistance wire on the rheostat? Why?
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- 11. Why is Archimedes's lever principle the same type of shovel, what is the shovel?
- 12. Briefly talk about the similarities and differences of the use of lever principle between pliers and guillotine
- 13. Hang two groups of hook codes on both sides of the lever, adjust the number of hook codes or the position on the lever, so that the lever is balanced in the horizontal position. What is the purpose? Record___ 、___ 、____ 、______ Then hang a group of hook codes on the same side of the spring dynamometer, and the spring dynamometer should be pulled vertically upward for the purpose of? In use__________ The fixed pulley is called the fixed pulley_____ But you can____________ And change the direction of tension
- 14. In the experiment of studying lever balance, the nuts at both ends of the lever should be adjusted so that the lever is balanced in its original position. At this time, when the lever is still balanced in its original position after the two ends of the scale are hooked, the distance from the point of action of the force to the fulcrum is equal to that of the force----
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- 17. What kind of lever is the balance? What principle does it use?
- 18. Why should the balance beam be made equal arm
- 19. What factors are related to the mechanical efficiency of leverage
- 20. What are the rules of mechanical efficiency of pulley block? The more hook yards, the greater the mechanical efficiency