Let the resistance of the aircraft in flight be proportional to the square of the speed. If the actual power of the engine is p when the aircraft is flying at a constant speed of V, then the actual power of the engine is p when the aircraft is flying at a constant speed of 2V______ P．

Let the resistance of the aircraft in flight be proportional to the square of the speed. If the actual power of the engine is p when the aircraft is flying at a constant speed of V, then the actual power of the engine is p when the aircraft is flying at a constant speed of 2V______ P．

Let f = Kv2 be the resistance of the aircraft in flight. When the aircraft is flying at constant speed, the resistance of the aircraft is equal to the traction of the aircraft. Therefore, when the aircraft is flying at speed V, P = FV = Kv2 · v = Kv3. When the aircraft is flying at constant speed 2V, P ′ = f ′ V ′ = K (2V) 3 = 8p, so the answer is: 8

Is the air resistance proportional to the velocity or the square of the velocity

Look at the speed. The higher the speed, the higher the times

Given that A.B.C is a rational number and a + B + C = 0, then a & sup2; + B & sup2; + C & sup2; - BC CA -- AB = ()

2(a²＋b²+c²-bc-ca--ab)=2a^2+2b^2+2C^2-2bc-2ab-2ca=2a^2+2b^2+2C^2-[2bc+2ab+2ca]=2a^2+2b^2+2C^2-[bc+ab+ca+ab+bc+ca]=2a^2+2b^2+2C^2-[b(c+a)+a(c+b)+c(b+c)]=3(a²＋b²+c²)a²...

There are 300 male and female students in total, with an increase of 25% for male students and 20% for female students, with a total increase of 13. How many male and female students are there respectively?
Urgent! It's mainly analysis! The formula should be complete! It should be able to understand!

Suppose there are x boys, then girls are (300-x). According to the meaning of the question: (1 / 25) x + (1 / 20) (300-x) = 13, we can get: x = 200 (people) 300-x = 300-200 = 100 (people), that is, there are 200 boys and 100 girls

x-75%x+85=6/7x

x-75%x+85=6/7x
x-3/4x+85=6/7x
X / 4 + 85 = 6 / 7X both sides multiply by 28 at the same time
7x+2380=24x
24x-7x=2380
17x=2380
x=2380÷17
x=140
I understand. Please accept,
If you have any new questions, please ask for help,

There are 14 boys and 18 girls in a class. Girls account for% of the class. Boys account for% of the class
Students account for about ()
Don't forget another problem. Boys make up about% of girls

Total class size: 14 + 18 = 32
Female ratio 18 / 32 = 56.25%
Male ratio 14 / 32 = 43.75%
Boys account for about 14 / 18 of girls = 77.8%

Square root and cube root addition and subtraction
√32—3√1/2+√2

√32—3√1/2+√2
=4√2—3/2√2+√2
=3√2—3/2√2
=3/2√2
3 / 2 √ 2

The unit price of a computer has been reduced by 1 / 5, which is equivalent to 20% discount

That's right!
Suppose that the original price of a computer is X. if the price of a computer is reduced by one fifth, it will be reduced by one fifth of its own price X. if the price is reduced, it will be equivalent to four fifths of the original price, that is, the price of 80% X
So it's equivalent to 20% off sales

Move the decimal point of a decimal two places to the right, and the number will increase by 100.98. What's the decimal? Five

Suppose the decimal is x, then the number obtained by shifting the decimal point to the right by 2 places is y, then: y = 100x, y = x + 100.98, 100x = x + 100.98, 99x = 100.98, the solution is x = 1.02

The ratio of number a to number B is 3:4, and the ratio of number B to number C is 6:7. What is the ratio of number a to number C? What is the ratio of number a, number B and number C?

The ratio of a to B is 3:4, the ratio of B to C is 6:7, the ratio of a to C is 9:14, and the ratio of a, B and C is 9:12:14