There are four types of physical plate problems

The frictional force experienced by m in the figure.

1) The graph is determined by the acceleration of m and m. When the m acceleration is greater than the m acceleration, the frictional force is: umg

When the acceleration is equal, the frictional force is: mf (m+m)2) figure when m acceleration is greater than m acceleration. As above, when the acceleration is equal, the frictional force is: mf (m+m).

In order for m to slide down m, then (1) in the figure, the acceleration of m is less than the acceleration of m, and (2) in the figure, the acceleration of m is greater than the acceleration of m, and this is used as a conditional column inequality solution.

If f acts on m, then the static friction is determined by f, acting force and reaction force. Then as long as f is greater than m, the maximum static friction that can be generated (which can be regarded as equal to the kinetic friction) is f>um).

If f acts on m, it is determined by the force of m on m. As long as the force of m on m is greater than the maximum static friction (um) that m can generate, m will slip.

In state (1), when the system reaches equilibrium, f=mg, so when f>mg, the small block will slide off the large block;

State (2) is the same as above, but the drop direction is different;

The maximum static friction is only related to the coefficient of friction of the contact surface and the pressure (in this case, gravity).

The effect of f is that both objects produce acceleration. As long as the acceleration ug (maximum at criticality) of m is less than the combined acceleration of both, the 、、、 can be slipped

Summary. There are four main types of situations.

When the pulling force is small, they are relatively stationary, there is static friction, and the two move together, what is the process in this?

There are four main types of situations.

The process is a process of uniform motion.

The resultant external force of the object is 0

The tensile force of the plank is equal to the kinetic frictional force.

The whole system moves forward at a constant speed.

Why when the pulling force is small, they are relatively stationary, there is static friction, and the two move together.

This is a state of physical analysis.

Defaults to stationary.

Otherwise, the object will break away from the plank and fall to the ground.

When this pull is smaller, which force does it refer to? Why do they have to be relatively stationary, there is static friction, and the two move together?

When the tensile force exceeds a certain value, the rolling force required to accelerate the skateboard exceeds the maximum static friction force of the skateboard on its observer, and the skateboard will slide relative to the slider.

This pulling force acts directly on the plank.

I just want to know why the tensile force is relatively stationary when the tensile force is relatively small. Why is there static friction? Why do the two move together? Why when the tensile force exceeds a certain value? Will they slide relatively?

This process is the interaction of the forces of the object and the plank along with inertia.

The object is subjected to inertia and falls to the ground.

Can you give an example of the answer to the question above?

Let's say you're on a bus.

The bus suddenly sped forward, and if you didn't hold the gauntlet, you would fall to the ground.

At this point, you're the object, and the bus is the plank.