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Why is the friction force and traction force of a car moving in a straight line at a uniform speed the same? Instead of traction greater than friction? The equilibrium force of a stationary object is equal. Why is the equilibrium force of uniform linear motion equal?
The trolley moves in a straight line at a uniform speed, the force is balanced in the horizontal direction, and the inevitable traction force is equal to the friction force
If the traction force is greater than the friction force, the trolley will accelerate evenly
Physical friction: the same car runs in a straight line at a constant speed of 20km / h and 60km / h respectively. Does their traction change? The same car runs in a straight line at a constant speed of 20km / h and 60km / h respectively. Does their traction change? If the traction force will increase and the two forces are in equilibrium due to uniform linear motion, and the traction force is equal to the friction force, the friction force will increase, and the friction force will not change with the change of speed,
That is, the car moves in a straight line at a uniform speed. According to Newton's first law, the external force it receives is 0, and the friction force is generally unchanged, so f = f, so why does the traction force remain unchanged and the speed increases? We can analyze it according to the power. The instantaneous power of the car can be expressed by P = FV, where p represents the instantaneous power, f represents
Questions about friction and traction Does the car start by friction or traction? I remember it's friction. The wheel gives the ground a backward force, and the ground gives it a forward friction. After it has moved, whether the engine or some other device gives the car a traction force to add speed, but according to w = FV, the greater the traction force, the smaller the speed. What's the matter, and what's the relationship between friction and traction? Please be clear and easy to understand, Wrong number, P = FV
The movement of the car always depends on friction, because only this force is the same as the direction of movement. In actual car work, its output power changes, but in the process of movement, it can be found that when a heavy car goes uphill, the car has to slow down in order to increase the traction. In fact, this traction is a force to the ground backward, Then forward motion is provided by friction
Increase or decrease friction Rubber particles on table tennis racket:______________________________ Studs on football shoes: _________________ Nicks on cement road: _________________ Brake hard to stop the car quickly: ____________ The bottom of the sled should be smoother: _____________
Rubber particles on table tennis rackets: increasing friction
Studs on football shoes: increase friction
Scoring on cement road: increasing friction
Brake hard to make the car stop quickly: increase friction
The bottom of the sled should be smoother: reduce friction
On the problem of physical sliding friction A steel skateboard sled, together with the goods on the sled, weighs 10000 n. on the horizontal ice surface, the horse can pull the sled at a uniform speed with 200 N in the horizontal direction. If the horse pulls the sled with 250 n, what is the motion state and friction force of the sled? If the horse pulls the sled with 150n, what is the motion state and friction of the sled? If you pull a distance of 200N and then reduce it to 150n, what is the motion state and friction?
The horse can pull the sled forward at a uniform speed with 200N in the horizontal direction -- indicating that the sliding friction of the sled is 200N; It indicates that at least 200N pulling force is required to make the sled move (the maximum static friction is approximately equal to the sliding friction)
1. If the horse pulls the sled with 250N, the motion state and friction of the sled are - the tension is 250N, which is greater than the sliding friction, and the sled accelerates. The friction is 200N
Because the sliding friction is only related to the roughness and positive pressure of the contact surface. Once it moves, as long as the roughness and positive pressure of the contact surface remain unchanged, the sliding friction will remain unchanged. In this problem, on the horizontal ice surface, the positive pressure is equal to gravity. The total weight 10000n remains unchanged, that is, the positive pressure remains unchanged. All are ice surfaces, and the roughness remains unchanged, so the sliding friction will remain unchanged
2. The horse pulls the sled with 150n, and the movement state and friction force of the sled are - the tension force is less than 200N, so it cannot be pulled, indicating that it is subject to static friction force at this time. In addition, if it is not pulled, that is, the object is still, static is a balanced state, and the force is balanced. In the horizontal direction, the tension force and friction force are balanced, so the friction force is equal to the tension force, which is 150n
Supplementary questions:
If you pull a distance of 200N and then reduce it to 150n, what is the motion state and friction—————— When you reduce to 150n, the pull is less than the sliding friction, and the sled will accelerate until it stops. But before stopping, it is still moving or sliding friction, and the size is still 200N. After stopping, it is stationary and subject to static friction, and the size suddenly changes to 150n
How to draw the schematic diagram of sliding friction in physics? Sliding friction acts on the contact surface of two objects. Where are the line segments and arrows drawn in the friction diagram? Is it the center of gravity or the contact surface of the object?
This should be painted on the contact surface, not on the center of gravity. I'm from Changsha University of technology, and my email is zhangdong2 [email protected]. You can email me. I'm very strong in this regard
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