What is a in F = ma? What does a mean when the rocket accelerates up?

What is a in F = ma? What does a mean when the rocket accelerates up?

A is acceleration, in meters per second. It refers to the speed of speed change. In short, it is the speed of speed. This is not difficult to understand. Just look at the definition in the book
When the rocket goes up, it's also acceleration. You mean going up, so acceleration is up, acceleration is vector, there is direction

The definition of F = ma
What force is f derived from this formula? Under what circumstances can this formula be used?

In the case of macro acceleration, the upper limit of macro acceleration can be used at lower speed

What does f-f = ma mean?
What does this equation represent? What is force friction?
What is the force (f), why f = MxA? Is a force equal to acceleration and mass?
When f is constant, the acceleration is inversely proportional to the mass. Who can give an example?

This formula should be written as (f-f) / M = a, the force minus friction divided by mass equals acceleration. The relationship between acceleration and mass, force is a = f / m, (F is the resultant force of all forces on the body). Obviously, f = m * a, force is constant, acceleration and mass are inversely proportional

Two identical spherical conductors, suspended at the same point by thin insulated wires of 13 cm in length, have the same amount of charge (can be regarded as point charge). Due to electrostatic repulsion, the distance between them is 10 cm. The mass of each spherical conductor has been measured to be 0.6 g, and the amount of charge they carry is calculated. (known electrostatic constant k = 9 × 109 n · m2 / C2)

Let the rope length be l and the distance between the two balls be D, then the force on the ball is as shown in the figure: because the ball is in equilibrium, there are: ftcos θ = Mg & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & n

The problem of Coulomb's law
Two balls A.B. of the same mass are successively hung on the two thin wires. The pulling forces of the upper and lower thin wires are F1 and F2 respectively. Now the two balls are charged with the same charge. At this time, the pulling forces of the upper and lower thin wires are F1 ', F2', respectively. Compare F1 with F1 'and F2 with F2'

This is the application of the whole method and the isolation method,
1. First of all, the integral method takes two spheres as a system, and the resultant force of internal force of the system is 0 (two Coulomb forces, etc.), so the resultant force only has the gravity of two spheres after the system is charged
F1'=F1
2. Post isolation method: now look at the charged ball B, B is subjected to the vertical downward Coulomb force and gravity, and the vertical upward rope pulling force F2 ', because B is stationary, so F2' = G2 + F (G2 is the gravity of B, f is the Coulomb force). When a and B are not charged, F2 = G2, we can see that F2 '> F2
3. Conclusion: F1 '= F1, F2' > F2

Coulomb's law and superposition principle can lead to Gauss theorem, so can Gauss theorem and superposition principle lead to Coulomb theorem

The Coulomb theorem can not be deduced from Gauss theorem plus superposition principle. The former and the latter are not equivalent. After further study, you will know that Gauss theorem describes the characteristics of electrostatic field as active field, while the characteristics of electrostatic field as irrotational field are given by ampere (loop) theorem, That is to say, Coulomb's law plus superposition principle and Gauss's theorem plus Ampere's (loop) theorem are equivalent in electrostatic field theory, Gauss's theorem only reflects one characteristic of electrostatic field
Specifically, the Gauss theorem of electrostatic field is proved without the radial and spherical symmetry of electrostatic field generated by electrostatic charge, so the Coulomb theorem can not be deduced from Gauss theorem plus superposition principle

How does Coulomb's law come out
How to know the proportion
There is also an inverse ratio
It is directly proportional to the amount of charge.
The imagination of the fifth floor is gravity. I know that
On the sixth floor
I mean the amount of charge. I know the distance

Experimental results show that the empirical formula

The problem of Coulomb's law
When two insulated metal balls with unequal electric charges are separated by a certain distance, the interaction force is F1. Now the two balls are separated to maintain the original distance after collision. Now the interaction force is F2, then
A if F1 is greater than F2, the two spheres will have different sign charges
B if F1 is less than F2, the two spheres have the same charge
It is impossible when CF1 = F2
D and ABC are all wrong

Choose D

It's about Coulomb's law,
It's Coulomb's law
An insulating spherical shell with radius r has a uniform charge of + Q, and another point charge of + Q is placed on the spherical center O. due to symmetry, the force on the point charge is 0

The key point of this problem is to find out the amount of charge at point B. with the amount of charge at point B, it is easy to solve according to the formula. Then how to find the amount of charge at point B? First of all, the problem should be understood

The subject of Coulomb's law
Two identical metal balls a and B, the distance r, the ratio of charge is 5:1, the Coulomb force of interaction is F. if they contact each other and then put back to the original place, the interaction force may be f___ F
Write down the process, thank you

For the same charge, the charge ratio is 3:3, F1 = k * Q1 * Q1 / R * r
F1：F=9：5 F1=9/5F
If the charge ratio is 2:2, the same is true for F2: F = 4:5
F2=4/5F