What is the principle of leverage
What is leverage
Children, isn't the seesaw we usually play in the park or community very interesting? In ancient times, people often used crowbars to pry up heavy big stones. Why did they use crowbars to pry up stones? In fact, these all use the principle of leverage. So what is leverage? What is the principle of leverage? Let’s learn about it with the elf Dudu!
Knowledge lever
The great "father of mechanics" Archimedes once said: "Give me a fulcrum and I can pry the entire earth." As long as solid objects that can rotate around the support point under the action of force are levers. Seesaw, scissors, wrench, , pry stick, etc. are all levers.
What is a lever
Lever is a rod that can rotate around a fixed point. It is a simple machine that can rotate around a fixed point on the rod under the action of external force.
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Principle of Lever
Lever has five important positions, namely five important points, namely fulcrum, power, power arm, resistance and resistance arm.
Leverage balance refers to the lever being at a stationary state or rotating at a constant speed under the action of power and resistance.
Application of the principle of leverage in life
The sitting board in each seesaw is actually a lever. The seating bracket serves as a fulcrum, also known as the balance point. In order to maintain balance on both ends of the seesaw, the same force needs to be applied at both ends of the seesaw.
, I believe that children are familiar with balances. Our scientific products are equipped with balances. The function of balances mainly has two , which are to measure the weight of objects and measure whether the weight of the two objects is equal. It also uses the leverage principle.
, crowbar
In the process of prying a big stone, the object that applies force to make the stone lift up is a crowbar.
4, scissors
scissors also use the lever principle. When the power arm is longer than the resistance arm, scissors save effort but work hard, such as vise . When the power arm is shorter than the resistance arm, the scissors are labor-intensive but labor-saving, such as the tailor's scissors.
Vide
Leverage in the human body
Leverage is indispensable in almost every machine, even in the human body there are many levers at work. Picking up something, bent over, or even raised your toes is the lever of the human body at work.
Lever in the human body
Complete the head lifting action, requiring the muscles at the back of the neck to provide power. The weight of the head is resistance, and the fulcrum of the lever is in the atlas and occipital joint, which is an iso-arm lever.
When you lift your heel and stand with the soles of your feet, the metatarsoropia joint at the toes is the fulcrum, the contraction of the calf muscles provides power, and weight is resistance. This is an labor-saving leverage . You can overcome greater gravity with smaller muscle tension.
. When flexing
When flexing the elbow, the fulcrum is in the elbow joint. The power is the contraction force of biceps , and the resistance is the gravity of the hands and elbows. The biceps can move the hands by a considerable distance as long as they are shortened a little.
The muscles and bones in the human body are intimate and form many levers, allowing us to walk, run, lift heavy objects, do radio exercises, etc.Is
very interesting? Children, have you understood what leverage is and the principle of leverage? Let’s find tools or objects that use leverage in life together!
Carry out scientific areas activities, stimulate the ability of children to scientific inquiry, and join the Elf Science Discovery Room Carry out scientific areas activities, stimulate the ability of children to conduct scientific inquiry, and join the Elf Science Discovery Room-
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