How is the formula for braking distance derived in traffic engineering?

It is related to the ratio of piston area at the inlet and return ends.

Hydraulic fluids. Fill the cylinder.

The velocity of the inlet chamber and the movement of the cylinder rod are the same.

The hydraulic oil enters the cylinder, and the stroke of the cylinder rod is S, the running time is t, and the speed of the cylinder rod is VThe formula is expressed as v=s t

Let the volume of the oil inlet chamber be v and the piston area of the inlet cavity be a, then v=s·aIf the displacement of the pump is q, then the flow rate of the oil inlet is also q, v=q·tt=s·a q

The synthesis is v=s s·a q=q a.That is, the operating speed of the cylinder rod is equal to the flow rate divided by the area of the piston of the inlet chamber.

In fact, the piston area of the two chambers of the differential cylinder is different (minus the cross-sectional area of the cylinder rod), and when the oil is fed and returned to each other, because the displacement q of the pump is unchanged, T1 T2=A1 A2That is, the running speed ratio is equal to the area ratio of the two ends of the piston.

For example: the usual differential cylinder, the general cylinder rod cross-sectional area is 1 2 of the piston area, and the other end is the rodless cavity is the piston area. Such a differential cylinder speed ratio is 1:2.

Differential connection, generally put the hydraulic cylinder.

The oil inlet and return oil are connected together, and the rod cavity oil of the oil cylinder is hydraulically returned to the rodless cavity to increase the speed at which the hydraulic cylinder stretches out, and this connection mode is generally used in the fast process of no load or small load, and it is to improve the movement speed at the expense of the output force. The differential connection is made without adding a hydraulic pump.

An effective way to achieve fast movement under the premise of flow rate.

vt2-v02=2as

s=v02/2a

The unit of v0 is km h, which is converted to m s, and the coefficient is.

In addition, both the adhesion coefficient and the longitudinal slope are important components of a, and the conversion formula between the two requires a coefficient g, and the value of g is .

Combined coefficient = 2*.

Therefore, the denominator will appear with the number 254.

In physics, there is a formula for a good stool: v end -v beginning = 2as brake speed beam sock absolute by the average value of driving.

v becomes 0, you can see the speed from 0 to v in reverse, then v at the beginning = 0 into the formula s = v end 2a I wish you good progress and all the best! If you don't understand, you can ask Oaks, and you are satisfied^

When braking, the speed changes from having speed to 0. The uproar is regarded as 0 at the end of the line. The square of the negative initial velocity is equal to the acceleration of the braking distance divided by twice the positive orange distance.

And because the acceleration is negative. So two minus signs cancel out. The final square of the initial velocity is equal to the acceleration at twice the braking distance.

There is such a good stool formula in physics: v end 0 5-v beginning 0 5 = 2as brake beam socks absolute speed from the average value v to 0, can be seen backwards as the speed from 0 to v, then v beginning = 0 into the formula s = v end 0 5 2a I wish you to learn rubber and make progress, everything goes well! If you don't understand, you can ask, and you are satisfied^

Think of the braking process as an anti-comic and a homogeneous addition, v. =0，v'=v initial formula: v' 0 5-v. 0 5=2as, i.e., v at the beginning 0 5-0 0 5=2ass=v at the beginning of 0 5 2a