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Are the objects on the horizontal conveyor belt subject to friction The conveyor belt is horizontal with an object moving forward at a uniform speed. Is this object subject to friction? If it's moving from rest to uniform speed, is there friction
The necessary condition for the generation of friction is that there is a relative movement trend between objects. If there is no relative transportation trend, there will be no friction. When moving at a uniform speed, the speed of the object and the conveyor belt is the same, and there is no relative movement trend, so there is no friction between the two. If it is from static to uniform speed, the object will naturally be subjected to friction, and the object will get acceleration by friction, Until it accelerates to the same speed as the conveyor belt
How to judge the friction force on the object on the conveyor belt?
When the object is placed on the conveyor belt moving at a uniform speed with an initial speed of 0, it moves backward relative to the conveyor belt, so it moves forward by friction. After the object accelerates to the same speed as the conveyor belt, it is stationary relative to the conveyor belt, so it moves at a uniform speed with the belt without friction
The object placed on the conveyor belt remains relatively stationary with the conveyor belt. Is it subject to friction
1. Just put it on, it is subject to friction, and the direction is the same as that of the transfer belt
2. When the speed is equal to that of the conveyor belt, the combined external force is zero
If it is subjected to friction, it must have a traction
It can be seen from the subject conditions that such a traction force does not exist
Therefore, it is not affected by friction
Why is the object subject to forward friction when it is first placed on the conveyor belt
To be exact, it should be why the object is subjected to forward friction when it has nowhere to go. Because the conveyor belt is moving forward and the object remains stationary due to inertia, it tends to move backward relative to the conveyor belt, so it will be subject to forward friction. Similarly, as long as the initial speed of the object is less than the speed of the conveyor belt
Why is the friction force on the conveyor belt along the speed direction of the conveyor belt?
The object is placed on the conveyor belt, the conveyor belt moves forward relative to the object, and the object moves backward relative to the conveyor belt, so it receives a forward friction, which provides the power for the object to move forward
The horizontal disc rotates at a uniform speed around the central axis. On the disc are... Two small objects a and B, which rotate with the disc. Their masses are M1 and M2 respectively, and the distances from the rotating shaft are R1 and R2 respectively, and R1 > R2. The friction coefficient between the two objects and the disc is the same, and their static friction forces are F1 and F2 respectively. The following statement is correct: A. The static friction force of two objects moves in their respective directions B. The friction force on both objects points to the center o C. F2 must be greater than F1 D. Increase the speed, and the object B starts to slide first Pure hand, fingers numb ~
Positive answer B
Static friction provides centripetal force a wrong b right
f=m ω^ 2R C cannot determine C error
along with ω Increase F and a to reach the maximum static friction first and slip first
RELATED INFORMATIONS
- 1. As shown in Figure 2, a disk rotates at a uniform speed around the vertical axis passing through the center in the horizontal plane, and a small object on the disk is stationary relative to the disk and moves with the disk. The centripetal force on the object is correct in the following statement: a A. The direction of the centripetal force points to the center of the disc B. the direction of the centripetal force is the same as the speed direction of the object C. The centripetal force direction is parallel to the rotating shaft D. the centripetal force direction remains unchanged The disc rotates counterclockwise
- 2. When the wood block with mass of M = 1kg is stationary on the platform with height of H = 1.2m, the dynamic friction coefficient between the wood block and the platform As shown in the figure, the wood block with mass of M = 1kg is still at the height of H = 1.2m Dynamic friction coefficient between wood block and platform on platform μ= 0.2, with horizontal thrust f = 20n, Remove the wood block when it has a displacement of S1 = 3M, and fly out of the platform when it slides again and S2 = 1m, Find the speed of the wooden block when it falls to the ground? ( )
- 3. As for friction, the correct one in the following statement is () A. The direction of sliding friction is always opposite to the direction of motion of the object B. Sliding friction always hinders the relative motion between objects C. The magnitude of the friction force must be proportional to the pressure between the contact surfaces D. The direction of friction can be perpendicular to the direction of motion of the object
- 4. Why should the trajectory of the particle with the longest flight time in a magnetic field be tangent to the boundary of the magnetic field
- 5. The wood block with mass m is placed on a smooth horizontal plane, and the bullet with mass m is fired in the horizontal direction at velocity V0 and finally remains in the wood block and moves with the wood block in V A,FL=1/2Mv2 B.Fs=1/2mv2 C.Fs=1/2mv02-1/2(M+m)v2 D.F(L+s)=1/2mv02-1/2mv2 The wood block with mass m is placed on a smooth horizontal plane, and the bullet with mass m is fired in the horizontal direction at velocity V0 and finally remains in the wood block and moves with the wood block in V. It is known that when the bullet is stationary relative to the wood block, the wood block advances L, and the depth of the bullet entering the wood block is s. if the resistance F of the wood block to the bullet is constant, then
- 6. A horizontal disc with radius r rotates at a constant angular velocity W. a person with mass m wants to go from the edge of the disc to the center of the disc. What is the attack of the disc on him? The answer is - 1 / 2MR ^ 2W ^ 2
- 7. Can potatoes specially made for potato planting eat I ate specially made green potatoes. Does it affect my health
- 8. A student is holding a small umbrella in the rain. The radius of the edge of the umbrella is R and higher than the horizontal ground h. When the umbrella rotates at an angular speed W, the umbrella throws out from the edge of the umbrella and forms a circle on the ground. What is the radius of the circle?
- 9. The magnitude of sliding friction is related to the pressure on the contact surface and the roughness of the contact surface The size of sliding friction is related to the pressure on the contact surface and the roughness of the contact surface. Please design a simple experiment to verify that the size of sliding friction is related to the pressure on the contact surface. In addition to long wooden boards, there are iron blocks, aluminum blocks and wood blocks of the same quality. Each block is fixed with a small metal hook for traction, Fixed pulley, spring dynamometer, several thin wires
- 10. Does the dog pull the sled in a uniform circular motion with constant acceleration?
- 11. Four conditions for friction Is it 1. Objects contact and squeeze each other 2. The contact surface is not smooth 3. Relative motion or relative motion trend between objects 4. There is elasticity between objects
- 12. If the three sides of an obtuse triangle are a + 1, a + 2 and a + 3, the value range of a is __
- 13. There are four line segments with the length of 1.2.3.4 respectively. The probability that any three of them will form a triangle is
- 14. The resultant force of each force on an object moving in a uniform circular motion must be a centripetal force Why is it wrong
- 15. The centripetal force of an object in uniform circular motion is a constant force, right?
- 16. Right triangle area formula
- 17. How to prove the formula of the relationship between the radius of the inscribed circle and the trilateral of a right triangle?
- 18. How to determine the direction of friction in physics?
- 19. Determine the direction of friction Many books explain that a bicycle moves at a uniform speed when it is stepped on by people, so the front wheels are subject to backward friction The front wheel does not rotate forward as the rear wheel does. Why is the rear wheel backward and the front wheel ahead? thank
- 20. Why can the direction of friction be perpendicular to the direction of motion of an object?