The magical use of old skating wheels

Old roller skates can be used as lifting mechanisms.

Pay attention to the movement direction and speed of the big and small gears. Its main function is to transfer the power of the power machine to the working machine and change the speed or direction of movement. Simple machinery such as axles, pulleys and gears are widely used in production and life. Use these simple mechanical energy to improve work efficiency. 3. The wonderful use of the wheel (the first lesson) The application of lever types gives examples of labor-saving lever, laborious lever and effortless lever to review old knowledge. Thinking: Talk about the inconvenience of these levers? Activity 1: lever and axle fulcrum force point resistance point force point o o fulcrum o resistance point axle is a machine composed of a round wheel and a shaft like a steering wheel, called axle. What is an axle? Axle group discussion: where is the axle still used in life? Power Point Pencil Sharpener Axle Axle Door Handle Axle adjustable wrench Axle Axle Axle Windmill Axle Electric Fan Axle Activity 2: Cleverly use the "wheel" as the pulley at the top of the flagpole, and the pulley that cannot rotate in one position is called the crown block.