All formulas in the first volume and all formula units in the second volume, from electric energy meter and electric power to household circuit and safe use of electricity, should also be included

All formulas in the first volume and all formula units in the second volume, from electric energy meter and electric power to household circuit and safe use of electricity, should also be included

Velocity V (M / s) v = s / T (s:: distance; t:: time) gravity g (n) g = Mg (M: mass; G: 9.8n/kg or 10N / kg) density ρ (kg / m3) ρ = m: mass / V: Volume (M: mass; V: Volume) buoyancy f floating (n) f floating = g matter-g liquid (g liquid: gravity of object in liquid) buoyancy f floating (n) f floating = g matter (this formula only applies to floating or suspending object) buoyancy f floating (n) F floating = g row = m row, g = ρ liquid GV row (g row: the gravity of the discharged liquid; m row: the mass of the discharged liquid; ρ liquid: the density of the liquid; V row: the volume of the discharged liquid, The equilibrium condition of lever f1l1 = f2l2 (F1: power L1: power arm F2: resistance L2: resistance arm) fixed pulley f = g object s = H (F: the tension on the free end of the rope; G object: the gravity of the object; s: the moving distance of the free end of the rope; H: the distance of the object rising) moving pulley f = (g object + G wheel) s = 2 h (g object: gravity of object; G wheel: gravity of movable pulley) pulley block f = (g object + G wheel) s = n h (n: number of segments of rope passing through movable pulley) work w (J) w = fs (F: force; s: distance moving in the direction of force) useful work w have total work w have = g object h w total = fs (suitable for pulley block vertical placement) mechanical efficiency η = × 100% power P (W) P = w / T (W: work) t: Time) pressure P (PA) P = f / S (F: pressure s: stressed area) liquid pressure P (PA) P = ρ GH (ρ: density of liquid; H: depth (vertical distance from liquid surface to the required point) heat Q (J) q = cm △ t (c: specific heat capacity of material, M: mass; △ T: change value of temperature) heat released by fuel combustion Q (J) q = MQ (M: mass; t: temperature change value); q: Calorific value) series circuit: current I (a) I = I1 = I2 = Voltage U (V) u = U1 + U2 + Resistance R (Ω) r = R1 + R2 + Parallel circuit: current I (a) I = I1 + I2 + (the main current is equal to the sum of the branch currents (shunt) voltage U (V) u = U1 = U2 =...) Resistance R (Ω) 1 / r = 1 / R1 + 1 / r2 + Ohm's law I = u / R (the current in the circuit is directly proportional to the voltage and inversely proportional to the resistance) current definition I = q / T (Q: charge (Coulomb); t: time (s) electric work w (J) w = uit = Pt (U: voltage I: current T: time p: electric power) electric power P = UI = I & sup2; r = u & sup2 / / R (U: voltage I: current 1. Mechanics)
Physics formula derivation problem online, etc. ~ ~ Xie v = at-x / 2T, please explain
V = at-x / 2T x a t denote the displacement acceleration time respectively. Please use the unit relation of physical quantity to explain this problem
I don't know if this problem is wrong. I haven't worked it out for a long time. If it's wrong, please tell me. If it's right, please write down the detailed steps
There is a basic condition for a physical formula: the dimensions (units) on both sides of the formula should be the same
In the above formula, the unit of V is m / s, the unit of X is m, the unit of a is m / S ^ 2, and the unit of T is s
So the unit of at is (M / S ^ 2) * s = m / s
The unit of X / 2T is m / s
The dimensions on both sides of the formula are the same, that is, the units are the same
Should v be the initial velocity?
There is x = VT + 1 / 2 * a * T ^ 2
SO 2 * V = x / 2T at
It's not your one
What's the matter with you?
It seems that this topic is not a test
But the relationship between the test units?!
The purpose of the question is to ask you the unit of V
Then let's deduce the unit of at-x / 2T
See if they're consistent
It should not be for you to deduce the formula
Vt = V0 + at. This is the formula for calculating speed: your problem requires the explanation of the unit relation of physical quantity. The unit of V is m / S? The unit of a * t is: [M / (s * s)] * s = m / S; the unit of X / (2t) is also m / s. According to the unit relation, this equation holds. Your question is about unit system, isn't it?
I hope I can help you.
You can't believe the exercises completely, because it's easy to make mistakes in printing or editing;
Ignore it and make a new one.
It's a good thing to study, but you can't drill in the horns!
Derivation of physical formula
The origin of the formula x = V0 * t + 1 / 2at ^ 2
If you are a high school student, you can't understand it even if I push it to you. Just take it as the conclusion of the experiment
How to deduce the physical formula I = nev
I=q/t=neSL/t=neSv
Current density j = I / S = nev
45 × 99 = (), the following formula () is wrong. A, 45 × (100-1) B, 45 × 100-45 C, 45 × 100-1
45 × 99 = (c), the following formula () is wrong
A、45×(100-1) B、45×100-45 C、45×100-1
C
62 wrong answer 5 questions, the error rate is how many. How to calculate. Seek the formula. The younger brother mathematics is not talented
62x0.05 = 3.1 error rate. The correct rate of the whole question: 100% - 3.1% = 96.9%
Is that right
Number of wrong questions / total number of questions × 100% = error rate
5÷62×100%≈8.06%
5/62*100%≈8.1%
Divide the number of wrong questions by the total number of questions and multiply by 100%
According to the formula, it's right
5/62＝8%
One day, a young man came to boss Wang's shop and bought a gift. The cost of the gift was 18 yuan, and the price was 21 yuan. As a result, the young man took out 100 yuan to buy the gift. Boss Wang didn't have any change at that time. He exchanged the 100 yuan for the neighborhood's change, and gave it to the young man 79 yuan. But the neighborhood later found that the 100 yuan was counterfeit money, and boss Wang had no choice but to return the neighborhood's 100 yuan. Now ask The question is: how much did boss Wang lose in this transaction
A. 179 yuan B. 97c. 100 yuan D. 118 yuan
∵ total payment 79 + 18 + 100 = 197, total income 100 + 100 (counterfeit currency) = 100, ∵ 197-100 = 97
Given that OC is the angular bisector of ∠ AOB, the error in the following expression is:
A. ∠ AOC = 1 / 2 ∠ AOB
B、∠aob=2∠boc
C、∠aoc=∠cob
D. 0 = 2 AOC = 2 cob = 2 1 = 2 cob (note that 1 is AOC and 2 is COB)
D. 0 = 2 AOC = 2 cob = 2 1 = 2 cob (note that 1 is AOC and 2 is COB)
The reason for the error is that ∠ AOB can't say ∠ o, and ∵ goes through more than one angle of o point
D. The meaning of ∠ 0 is not clear
D is wrong
∵ when an angle is large, it should be represented by three letters
Obviously a is wrong
It should be D, not angle o
Do you have any pictures
For a large number of high school pure mathematical problems) can be
I am poor in calculation
You have poor calculation ability. You can solve it in this way. You can throw away the answers behind your math and physics problems in the future. When you do the problem, don't correct the answers. When you finish it, put it aside. You can do it again in a few days. Check with your previous answers. When you finish it, your answers are the same. You
Go to the book city and buy some exercise books. If you are in senior three, there are many questions in the three-year college entrance examination and five-year simulation, and they are all college entrance examination questions, you can have a look
I can't remember some physical formulas. How can I remember them?
It's very troublesome to remember the formula in physics, so it's better to remember the basic formula, and then deduce other formulas from the basic formula
Back, also can rely on practical activities to recall, flexible application, practice makes perfect. Or only you know the answer
The basic formula, and then derive other formulas from the basic formula
Make a question