Divide a number by 5 out of 8 to get 5 out of 6?

Divide a number by 5 out of 8 to get 5 out of 6?

Let the number be x, that is, the formula is x / (5 / 8) = 5 / 6, that is, 6x = 5 * (5 / 8), that is, 6x = 25 / 8, and x = 25 / 48. Omitting two decimal places is 0.52

The formula of 5 / 2 / 6 + 8 / 5 / 15

7 and 8 / 15

Resistance R1 = 6ohm and R2 = 12ohm are connected in parallel in the circuit. The electric power consumed by R1 is 6W. How much voltage is the two ends of R1? (2) What is the total electrical power consumed by R1 and R2?

(1) ∵ R1 = 6 Ω, P1 = 6W, the voltage at both ends of R1 is: U1 = P1, R1 = 6 Ω × 6W = 6V. Answer: the voltage at both ends of R1 is 6V. (2) resistance R1 and R2 are in parallel, we can see that: u = U2 = U1 = 6V, ∵ R2 = 12 Ω, ∵ P2 = u22r2 = (6V) 212 Ω = 3W, then the total power consumed by R1 and R2 is: P = P1 + P2 = 6W + 3W = 9

When the vehicle starts from a standstill with an acceleration of 2m / S2, what is the speed of the vehicle at the end of the fifth second? What is the average speed of the car in the fifth second? What is the displacement of the car in the fifth second?

The speed at the end of the fifth second is: v = at = 2 × 5m / S = 10m / S; the displacement in the fifth second is: X5 = 12at52 − 12at42 = 12 × 2 × (25 − 16) M = 9m. Then the average speed in the fifth second is: v = x5t5 = 91m / S = 9m / s. A: the speed of the car at the end of the fifth second is 10m / s, the average speed in the fifth second is 9m / s, and the displacement in the fifth is 9m

Complete square formula in the second grade of junior high school
(1) Please fill in the blanks with "<" > "="
①3^2+2^2＿＿2*3*2
②5^2+5^2＿＿2*5*5
③ (radical 3) ^ 2 + (radical 2) 2 * radical 3 * radical 2
④（-6）^2+3^2＿＿2*（-6）*3
⑤（-2）^2+（-2）^2＿＿2*（-2）*（-2）
(2) Observe the above formulas and try to guess the size relationship between a ^ 2 + B ^ 2 and 2Ab;
(3) Can you prove your conjecture with the help of the complete square formula? Try it!

(1) Please fill in the blanks with "<" > "="
①3^2+2^2＿>＿2*3*2
②5^2+5^2＿=＿2*5*5
③ (radical 3) ^ 2 + (radical 2) ^ 2 > (2 * radical 3 * radical 2)
④（-6）^2+3^2＿>＿2*（-6）*3
⑤（-2）^2+（-2）^2＿=＿2*（-2）*（-2）
(2) Observe the above formulas and try to guess the size relationship between a ^ 2 + B ^ 2 and 2Ab;
a^2+b^2>=2ab
(3) Can you prove your conjecture with the help of the complete square formula? Try it!
Because: A ^ 2 + B ^ 2-2ab = (a-b) ^ 2 > = 0 (when a = B, it is 0)
So: A ^ 2 + B ^ 2 > = 2Ab

The stiffness coefficient of a spring is 2 × 103n / m, and its original length is 40cm. In order to produce 200N elastic tension, the spring should be extended to

F=kX
200=2000X
x=0.1m

How many kilos is one kilogram equal to?

The exact answer (in Encyclopedia): one kilogram = one kilogram = 1000 grams, but it's called differently,

When an object is hung on the spring scale, the reading is 19.6n, and when it is immersed in water, the reading is 4.9n? (2) What's the volume of this object? (3) What is the density of this object?

(1) The buoyancy of an object is f-floating = G-F = 19.6n-4.9n = 14.7n; (2) because the object is immersed in water, the volume of the object is equal to the volume of the water it discharges: v = V row = f-floating, ρ water g = 14.7n1.0 × 103kg / m3 × 9.8n/kg = 1.5 × 10-3m3; (3) the mass of the object is m = GG = 19.6n9.8n/kg = 2kg, the density of the object is ρ = MV = 2kg1.5 × 10 − 4m3 ≈ 1.33 × 103kg / m3 The buoyancy is 14.7n; (2) the volume of the object is 1.5 × 10-3m3; (3) the density of the object is 1.33 × 103kg / m3

It is known that the area of a rectangle is (3a & # 178; + 7a-6) CM & # 178;, and the length of one side is (A-2 / 3) cm;

（3a²+7a-6)
＝（3a-2）(a+3)
=3(a-2/3)(a+3)
=(3a+9)(a-2/3)
So the length is 3A + 9

On the ceiling of the elevator, a small ball is suspended by a light spring. When the elevator is stationary, the elongation of the spring is 4cm. When the elevator is running, the elongation of the spring is 3cm. Then the movement of the elevator is ()
A. Accelerate and decrease with a = 14g acceleration B. accelerate and decrease with a = 34g acceleration C. decelerate and increase with a = 14g acceleration D. decelerate and increase with a = 34g acceleration

Let the mass of the ball be m and the stiffness coefficient of the spring be K. at rest, Mg = kx1. When the elongation of the spring decreases, the elastic force decreases. The resultant force of the ball is vertical downward and the acceleration of the ball is vertical downward. According to Newton's second law, mg-kx2 = ma, X2 = 34x1 is substituted into the solution, a = 14g = 2.5m/s2, and the direction is vertical downward