There is a probability problem of the occurrence of mutually exclusive events in mathematics A cube with color on each side is sawed into N3 cubes (n is greater than or equal to 3) of the same size, and the probability of any one of these cubes with color on exactly two sides is zero The correct answer is 1 - (n-2) 3 / N3, and the main explanation is (n-2) 3 Sorry, I copied the wrong topic, at least one side of the probability of color

There is a probability problem of the occurrence of mutually exclusive events in mathematics A cube with color on each side is sawed into N3 cubes (n is greater than or equal to 3) of the same size, and the probability of any one of these cubes with color on exactly two sides is zero The correct answer is 1 - (n-2) 3 / N3, and the main explanation is (n-2) 3 Sorry, I copied the wrong topic, at least one side of the probability of color

Cut a cube with color on each side into n ^ 3 cubes (n is greater than or equal to 3) of the same size, divide the edges into N equal parts, and the number of blocks with color on exactly two sides is 12 * (n-2)

Find the acceleration formula, the formula when the initial velocity is 0 and the formula when the initial velocity is not 0

Some important corollaries of V = VO + at are as follows: (1) vt2 - V02 = 2As (uniform acceleration linear motion: A is a positive value, uniform deceleration linear motion: A is a positive value) (2) the instant velocity in the middle of a B segment: VT / 2 = = a s a T B (3) the instant velocity in the middle of a B segment displacement: vs / 2 = uniform velocity: VT / 2 = vs / 2; uniform acceleration or deceleration

The problem of rational number with negative number
It's better to add, subtract, multiply and divide,

Rational numbers are integers or infinitely circular decimals
2+(-3)=2-3=-1
2-（-3）=2+3=5
2*（-3）=-6
2/(-4)=-1/2=-0.5

The acceleration is 49 meters per second and the moving distance is 325 meters,

From the distance formula: S = v0t + at ^ 2 / 2
If the initial velocity is 0, the formula becomes s = at ^ 2 / 2
Brought in data: 325 = 49T ^ 2 / 2
The results show that t = (650 / 9) ^ (1 / 2) = 8.5s
According to the velocity formula v = at = 49 * 8.5 = 416.5m/s
I hope I can help you

50 oral arithmetic problems in grade three

360 ÷3 ＝ 42× 20＝ 12 × 50＝ 1500－700＝ 5900－4000＝ 76 ＋ 27＝ 840 ÷ 2＝ 770 ÷ 7＝ 30× 20＝ 40× 50＝ 9900+100＝ 700 ÷ 7＝ 240× 10＝ 390 ÷ 3＝ 60× 50＝ 71 - 22＝ 50 × 90＝ 14 × 20＝ 600...

What are the units of distance, velocity and acceleration?

Distance: M
Speed: M / S
Acceleration: one is Newton / kg (n / kg), the other is meter / second square (M / S & # 178;), the unit is different, the purpose is different, but the value is the same. If the unit of kg is international unit, it is m / S & # 178;, if it is a common unit, it is n / kg. 2 this price, n is kg * n / kg

What are the methods of mixed operation of rational numbers in junior high school?

This is the reality

Know the acceleration, know the time of speed change, how to find the moving distance of the object in this period of time

If it is the problem of high and medium uniform acceleration, then s = v0t + at & # / 2
If it is not uniform acceleration, then s = v0t + ∫ ADT

Thinking of mixed operation of rational numbers

The law of exchange and the law of combination should be considered. If the sign is the same, it is easier to calculate first

Acceleration, average velocity, deceleration and distance are known. How to calculate the motion time
The speed of the starting point and the ending point is 0. There are acceleration period, average speed period and deceleration period in the middle. The distance is known. What formula should be used to calculate the movement time?
thank you!

First, calculate the time from 0 to constant speed T1 = average speed / acceleration; then calculate the time from constant speed to deceleration T2 = average speed / deceleration; then calculate the distance S1 = (T1 + T2) × average speed / 2; then calculate the time T3 = (distance - S1) / average speed; finally, the sum of T1 + T2 + T3 is the movement time