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Is pulley a lever Why is pulley a deformation of lever? Isn't lever a hard rod? Can you make it clear
The principle of pulley is the same as that of lever``````
Generally, we regard the fixed pulley as an equal force lever, and the movable pulley as a labor-saving lever``
The fulcrum of the fixed pulley is the rotating shaft, so the power arm is equal to the resistance arm. To pull an object at one end, the other end needs an equal force, so the power is equal to the resistance, so the fixed pulley is an equal force lever; the fulcrum of the movable pulley is at the point where the fixed end of the rope is tangent to the sliding pulley, so the force arm of the tension is twice that of the gravity arm of the weight (when the rope is pulled vertically upward), So it's a labor-saving lever
Questions about pulleys in Junior Physics
1. A rope can bear a tensile force of 200N at most. A student wants to use this rope to assemble a pulley block. When he stands on the ground to pull the rope, he can make the object of 450N rise at a uniform speed. Please draw the assembly diagram of the pulley block (oral). If each pulley weighs 6N and the rope weight and friction are not included, what is the actual tensile force of the student?
2. Someone throws out a 10N ice block with force, and the ice block stops after sliding 40 meters on the horizontal ice surface
A. Man does 400j work on ice. B. gravity does 400j work on ice
C. Neither man nor gravity does work on ice
The more detailed the first question is, the better. I don't think C is the second one
1. Two pulleys (one fixed pulley and one movable pulley) the rope starts from the fixed pulley
Fra = g / N = (450N + 6N) / 2 = 228n
2.C
The condition for force to do work is that the object moves a certain distance in the direction of the force under the action of force. However, gravity is downward and the movement of ice is horizontal, so gravity does not do work on ice
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