Ask for a question about friction, a question about friction

Excluding the weight of the object: f(x)=f*fcos30°=f(y)=p-f*sin30°=30kn

fs=f*f(y)=

f(x)>fs hence the motion of the object.

The magnitude of the frictional force between the object and the ground is: Direction is horizontal to the right.

The force f is broken down into 10 kN upwards and 10 3kN horizontally to the left

Tensile Force》Maximum static friction (40-10)*

So exercise. Friction

Decompose f, up 10kN, forward 10kN=17kN, vertical resultant force 30kN down.

f dynamic = 12kn f static = 15kn

The object motion friction is 15kN

The component of f in the horizontal direction is 10 3, which is less than p*

So the object can't move.

The supporting force of the ground on the object n=p+fsin30. =40+20*1 2=50nStatic friction fStatic=f*n=

Left pull f left = fcos30. =20*

If the left of f is less than the rest of f, then the object is stationary and the frictional force is 25N

Please, the object has no mass, what's the matter???

There is no kn this unit, don't scribble.

1. V1=V2, and it is a constant velocity, so there is no friction between A and B, and B is subjected to the friction of the ground to the left;

2. When V1 > V2, A moves to the right relative to B, then it is subjected to the sliding friction force of B to its left, and B is subjected to the friction force of the ground to the left;

3. V1 hopes it will help you!

The gravity of the object is larger, and the object will fall at points P and Q, and the friction force will prevent it, so it will go up (I don't know if you are drawing it wrong, there is actually no friction at points P and Q, because the object has no pressure on the conveyor belt).

The rear wheel of the bicycle is the driving wheel, which rolls backward and rubs it to stop it, so the friction force is forward, while the front wheel is the driving wheel, and the roll backward is driven by the friction force of Mo Congchang, so the friction force is backward.

Remember that friction always helps the weaker side, and then analyze the specific problem on a case-by-case basis (the gravity of points p and q is strong, and there is no force to Zheng or upstream, so friction helps upwards).

1 b 2 b 3 b 4 b 5 b

Beneficial Friction: 12356

Question 5: aWheels rubbing the conveyor belt.

The direction is downward, and the conveyor belt rubs a wheel in the direction of upward.

The conveyor belt rubs the B wheel in the direction of the up, and the B wheel rubs the conveyor belt in the direction of the downward directionQuestion 1: There is no friction when a book is placed on the table.

Two magnets of the same name repel each other.

Transmission belts convey goods.

I understand what you mean, it's not good to draw, let's talk about friction first, although the distance between the two sticks has become larger, but the inclination angle has not changed, so the resultant force of the support force of the two sticks has not changed, that is, the positive pressure has not changed, so the friction force has not changed. The support force of a single stick becomes larger, because the opening angle becomes larger, but the component force becomes larger, as shown in the figure.

There is no picture and no truth.

If you follow the question, my understanding should be this: because the angle is not the same, the friction and support force are the same, so the cylinder should still slide down at a uniform speed.

A The object on the conveyor belt moves with the conveyor belt, the object is stationary relative to the conveyor belt, and the static friction force does positive work.

c The sliding friction of the object gliding on the rough table does not do work.

d The sliding friction of the object on the rough table does not do work, and the friction on the object does the work, so the algebraic sum is not 0

2n At this time, the wooden block is stationary, and the gravity and friction are balanced, and the direction is opposite, so it is 2n

The force analysis of the upper cylinder yields that the pressure of the upper circle on the lower circle is three times the cylindrical gravity of the third of the root number. Perform a force analysis on the lower cylinder, receive the pressure of the upper cylinder on it, the ground support force n, the ground friction force f (horizontally pointing to the other bottom cylinder) and of course the gravity force, these four forces are balanced. In order to maintain the balance of simplicity and resistance, it is required that this friction force is less than the maximum static friction force.

It is possible to find the gravitational force of gravity (horizontal force balance) with a frictional force of three sixths of the root number and a support force of three-thirds. This means that this maximum static friction must be less than the desired friction. It can be concluded that the required minimum coefficient of sliding friction is the friction force divided by the ground pressure, and the result is a root of nine number three, that is, the coefficient of sliding friction between the cylinder and the ground must be greater than this value.

I'm talking about the relationship between the friction coefficient between the cylinder and the ground to be satisfied The recommended answer is the relationship between the cylinders that the friction force should be satisfied I think the friction relationship between the cylinders is generally not considered in the mausoleum, and the friction relationship between the cylinder and the ground is generally considered. But synthesizing our answer is certainly more complete.

<>l1l2 is the tangent of the circle.

The upper cylinder is stressed fn1=fn2 f1=f2。And then from the equilibrium condition:

This round 2 (fn2cos30+f2sin60)=mg 3fn2+f=mg )

Stress on the left cylinder: fn'sin30=f1'sin60fn'=√3f1'

i.e. fn = 3f).

F1=mg2 is obtained from (1) (2).

f1 = f2 = mg 2 fn1 = fn2 = 3mg 2 two static friction equal and magnitude mg 2

To balance all three cylinders, this friction force should be greater than the maximum static friction fnNamely.

fn＞mg/2

That is, the coefficient of sliding friction between cylinders only.

3 3, you can make three cylinders stacked on top of each other on the ground.

The upstairs is already nice.