Is it v = at or V = 1 / 2at? (v = V + at or V = V + 1 / 2at?) if it is v = at, what is x = VT + 1 / 2at ^ 2? How to push?

Is it v = at or V = 1 / 2at? (v = V + at or V = V + 1 / 2at?) if it is v = at, what is x = VT + 1 / 2at ^ 2? How to push?

V = V0 + at is the final velocity
V = V0 + 1 / 2at is the average velocity
It can be understood that the average velocity is used to calculate X
x=vt= v0 t+1/2at^2

Expression of measuring acceleration with dot timer
It's like I know that if only 5 or 7 segments of displacement are given, what's the expression of acceleration? For 4 segments, I know (X3 + x4-x1-x2) / 4T & # 178; and I want to know, for example, how to calculate the velocity at 3 o'clock when 5 segments are unique

aT²=ΔS
Speed at 3:00: V: (s5-s1) / 4T t = 0.02
Or (s4-s2) / 2T, t = 0.02

What does QE mean in physics

Q is the electric quantity, e is the electric field, and QE is the electric field force on the charged body in the electric field

How to derive e ^ A ^ 2, where e is the base of natural logarithm

A is unknown
(e^a^2)'=e^a^2*(a^2)'=e^a^2*2a=2ae^a^2
If you don't understand, I wish you a happy study!

Given that e is the base of natural logarithm, LNX is the logarithm function whose base is equal to e, let b > a > e, prove AlNb

Let f (x) = LNX / X
f'(x) = (1 - lnx)/x^2
When x > e, LNX > 1, f '(x) < 0
So f (x) is monotonically decreasing
b > a > e
So: F (b) < f (a)
lnb / b < lna / a
Multiply both sides by ab at the same time
alnb

Except for the irrational number π and the base e of natural logarithm
Besides the irrational number π and the base number e of natural logarithm, are there any other irrational numbers with practical value?
What is the base e of natural logarithm?

In fact, there is also a very important golden ratio, that is, 0.618... Is an irrational number, which is quite magical. The optimization method made by it is much faster than the dichotomy method. See Baidu for details, and I won't stop talking. "E is the 1 / x square of the limit (1 + x). When x infinitely tends to 0, people write the result as e for convenience

What is the base of natural logarithm

E = 2.71828 18284 59045 23536 02874 713526 (the 31st decimal place is rounded to 7)
Jiangsu Wu Yunchao answers for reference

Lim(1/n^3 +2^2/n^3 +3^2/n^3+… +N ^ 2 / N ^ 3) equals

Lim(n→∞)(1/n^3 +2^2/n^3 +3^2/n^3+… +n^2/n^3)
=Lim(n→∞)(1+2^2…… +n^2)/n^3
=Lim(n→∞)n(n+1)(2n+1)/6n^3
=Lim(n→∞)(1+1/n)(2+1/n)/6
=2/6
=1/3

LIM (n! + (n-1)! + (n-2)! + (n-3)

Coulomb's law of electrostatic field, electric field strength, electric potential energy, electric potential difference and so on

Coulomb's Law: F = k * Q1 * Q2 / R ^ 2
Q is the charge quantity, k = 9 × 10 ^ 9, R is the distance between two point charges
The electric field strength e = f / Q (definition), f is Coulomb force, q is the quantity of charge to test charge
E = u / D (for uniform electric field), u is the potential difference between two points, and D is the distance between two points along the electric field line
Potential energy increment w = u * q, potential difference u is the decrease of potential, u and Q are signed