How to calculate the friction force when the object accelerates

1. If it is a relative motion, it is only related to the pressure and sliding friction coefficient between objects, f = n μ， It has nothing to do with velocity and acceleration.

2. The project is located at the intersection of xishenhu road and Hezhong street in Suzhou Instrial Park, in the northeast of Jinji Lake, with a good geographical location and in the CBD business circle. The project consists of residential and commercial procts. Advantages: 1. The project has its own commercial body. In the later stage, it will be a comprehensive living area integrating residential, commercial, business and other forms. The living and commercial supporting facilities (including 20000 square meters of commercial, linglongwan neighborhood center, Jiuguang Department store, etc.) of the residents in the community will be relatively perfect. 2. Ecation support: Soong Ching Ling kindergarten and Xingwan school are all around the project. 3. Transportation: about 1km away from the Times Square Station of Metro Line 1, there are many bus stops. About 1.3km to the north of the project, there is loujiang expressway, and the project is close to the normal Expressway and Beijing Shanghai Expressway, so it is convenient for both self driving and relying on subway and bus. Disadvantages: 1. The project is built into a comprehensive living area, and the residents are messy. All in all, the project is suitable for customers who work in the park and have higher requirements for surrounding supporting facilities.

3. The reasons for the problem are as follows:
1
2. The TCP / IP settings of the computer setting the router are correct. The router is connected to adslmodem. Because the modem settings conflict with the default settings of the router, it is unable to enter the router settings page
3. The router is used in the existing network, which is 192.168.1.0 network segment, the same as the router's LAN network
4. Proxy server is set in browser
5. The computer setting the router uses multiple network cards, and the TCP / IP setting of the network card is wrong;

4. Acceleration, i.e; A physical quantity that describes the speed and direction of an object. If the speed of an object changes greatly and takes a short time, the speed changes quickly, that is, the acceleration is large, and vice versa. It can be seen that the acceleration is the rate of change of speed with respect to time. Unit: M / S2
definition of acceleration a= Δ v/ Δ T
definition of friction force: if two objects in contact with each other move relatively or tend to move relatively, a force hindering the relative motion will be generated on the contact surface of the two objects, which is called friction force, If two objects in contact have relative sliding, the force in contact is called sliding friction. The size of friction is related to the material of the contact surface and the smoothness of the surface, as well as the positive pressure between objects, First, we should judge whether the friction is sliding friction or static friction, and then calculate it by corresponding methods.
the calculation formula of sliding friction is f= μ N, where μ Dynamic friction coefficient, also called sliding friction coefficient, is only related to material and roughness of contact surface, but has nothing to do with contact area; N is the positive pressure

5. Let the acceleration of object B be y, then the friction force = B (kg) x (9.8-y)
or friction = B (pressure) x friction coefficient

6. As long as it moves relative to the surface, it is sliding friction force
F = UN
u is friction washing, and N is the supporting force of the surface to the object

7. For example,
an object
on a horizontal plane
moves uniformly in a straight line under a force of 120N in the horizontal direction
because the force is balanced
so the pulling force is equal to the friction force
that is, the friction force is equal to 120N (the static friction force reaches the maximum
that is, the dynamic friction force)
if the pulling force is changed to 150n
the object accelerates
because of the friction force The size of
is only related to the friction coefficient
pressure size
action area
and all of them are unchanged
so the size of
friction is also unchanged
it is still 120N (at this time
friction is dynamic friction)
if the pulling force is removed at this time
the object will decelerate
as above
the size and direction of friction remains unchanged
120N

8. The formula of sliding friction f = n μ， Is the sliding friction force = the pressure of the object on the bearing surface x the friction coefficient. As long as these two data are known, we can use this formula to calculate the friction force no matter what telecontrol it does.

9. This question is too general. Is tension a constant force or a variable force? Is acceleration uniform or variable? Is there an equation describing the force and acceleration? Or is there a velocity equation
if we know the expressions of acceleration and force, we can solve this problem by introcing non inertial frame. The difference between non inertial system and inertial system is that there will be one more inertial force in the non inertial system. Its direction is opposite to the acceleration direction. The magnitude is equal to the acceleration a times the mass m of the object. At this time, the object is regarded as equilibrium, and the friction can be obtained by using the equilibrium condition
if you know the velocity or displacement equation of an object, you can use the momentum theorem to solve it. The momentum theorem is MDV = ∑ FDT. This is a differential form. The expression of friction can be obtained by integrating the parameters