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Anonymous users2024-02-07If the tension increases from zero, the friction force decreases to zero after applying the tension force and then gradually increases along the inclined downward direction, and if you want to have acceleration upward, the tension force and the friction force cannot be in the same direction.
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Anonymous users2024-02-061) Use x=v0t+1 2at and vb=v0+at to find the acceleration a=3m s. vb=8m/s。
2) The second question you use f=ma to solve, f=ma=, the direction of the force is parallel to the upward slope, this is the final resultant force, and all the forces are gravity and tension at the beginning, you just need to draw these three forces, the resultant force is f, and the component force is gravity and tension. Because the component of this force can cancel out the gravitational force and produce a force parallel to the inclined plane. Calculate that it is.
Friction is opposite to the direction of motion, and friction and tension are not in the same direction.
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Anonymous users2024-02-05I've thought that way before, but it doesn't have to be that way.
If you think about the limit, move the tensile force parallel to the inclined plane up a little bit, the force parallel to the inclined plane is basically unchanged, the vertical component increases, the friction force decreases, and you can pull it with a smaller force.
You can list an equation along the inclined plane and set the angle to c
fcosc=mgsin+nu+ma
n=mgcos-fsinc
Simultaneous solution may be done by looking for a guide.
I'm lazy, so I don't care, if I'm wrong or can't do it, I need to ask.
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Anonymous users2024-02-04Tip: According to the triangle law of force, the gravitational force of small blocks, friction and tension and the magnitude and position of the resultant force are found in relation to the tensile force. Pay attention to the shape of the triangle, math problems. This kind of vector problem should draw more force analysis diagrams, which is very beneficial for problem solving.
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Anonymous users2024-02-03Question 1: According to the force analysis, the friction between AB and BC is G 2, and the friction between A and the left plate is (3G) 2
There is no picture in the second question.
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Anonymous users2024-02-02Question 1: The friction force is vertically upward, g is vertically downward, and f is horizontally to the right, if you want to be stationary, the three forces must be balanced, so the friction force is equal to the resultant force of g and f, f is equal to the square of g under the root number plus the square of f. In the same way, analyze the friction between A and B yourself.
Question 2: I don't know what the diagram looks like. Newton's second fixed green is a bridge between force and kinematics, and it should be solved with good f=ma.
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Anonymous users2024-02-01Do physics problems, do a good job of force analysis, and everything is OK
The generation of rolling friction is caused by the deformation at the contact point between the object and the plane. The object is pressed into the bearing surface by gravity, and at the same time it is also deformed by compression, so when rolling forward, the bearing surface in front of it is uplifted, which makes the point of action of the elastic force n of the support facing the object move forward from the lowest point, so the elastic force n and gravity g are not in a straight line, but form a force couple moment that hinders rolling, which is rolling friction. The magnitude of rolling friction is measured by the coupling moment, and is proportional to the positive pressure, and the proportional coefficient is called the rolling friction coefficient δ, which is numerically equivalent to the elastic force to the force arm of the center of mass of the rolling object, so it has a dimension of length; It is related to the material, hardness and other factors of the rolling object and the bearing surface, and has nothing to do with the radius. >>>More
The formula of sliding friction depends on the conditions of the question, if the object is in relative motion, that is, the object is in motion, and the contact surface between the object and the horizontal plane must be rough, that is, only the surface of the object is rough, the horizontal plane is not rough, or only the horizontal plane is rough, and the surface of the object is not rough, this formula cannot be used. When an object is subjected to gravity, it exerts a pressure on the plane, which in turn gives the object a supporting force. On the inclined plane, the gravity force is vertically downward, and the supporting force is vertically inclined upward, and the gravity needs to be orthogonally decomposed, decomposed into the vertical inclined plane direction and along the inclined plane direction, at this time, the component force of the gravity in the vertical inclined plane direction is equal to the supporting force received by the object, and the sliding friction force of the object can be found by substituting the formula of this force. >>>More
Definition of sliding friction: When an object slides relative to another object on the surface of another object, it is subjected to the force of another object that prevents it from sliding relative to each other, and this force is sliding friction. >>>More
The first question: if the pull does not move, it is 5n, and if the pull moves, it needs to be calculated according to the motion state. 2: >>>More
Heat generated by friction = sliding friction * displacement of the object relative to the conveyor belt. >>>More