An electric energy meter is marked with 3000r / kWh. If a 220 V electric appliance works alone for 3 minutes, and the electric energy meter turns 30 turns, what is the power and current of the electric appliance?

An electric energy meter is marked with 3000r / kWh. If a 220 V electric appliance works alone for 3 minutes, and the electric energy meter turns 30 turns, what is the power and current of the electric appliance?

An electric energy meter marked with 3000r / kWh indicates that 1kwh turns 3000 turns, a 220 V electric appliance works alone for 3 minutes, and the electric energy consumed by the meter turns 30 turns indicates that the electric energy consumed is 1 / 100 kwh = 36000 joules, so his power is 36000 ／ 3 ／ 60 = 200 Watts
Current I = 200 / 220 = 10 / 11 A
See?

Ask a math question and answer it well
If you use a plane to cut a cube, can you cut a hexagon? How?

A simple oblique cut out of a few regular trilateral cones is a polygon

Rated power 50 Hz rated power 500 W rated voltage 220 V
What's the difference between 50 Hz and 500 W
Heating for 3 minutes, cooling power 75W, rated power 500W, rated voltage 220V, how much electricity per hour

Hz is the frequency (also known as cycle), which refers to the number of times that the generator drives N and S-level coils to cut per second. The commercial AC in China is 50 Hz. W is the power, V is the voltage. Don't make a mistake

When m ≠ ± 1, the solution of the equation m (mx-m + 1) = x is X=___ ．

Remove the brackets, get m2x-m2 + M = x, transfer the term, get m2x-x = m2-m, merge the similar terms, get (M2-1) x = m2-m, the coefficient is 1, get x = mm + 1

Connect the 220 V and 60 W bulbs to the 220 V · 230 V and 200 V power supply respectively. What are their power

Resistance value of 220 V, 60 W bulb:
R＝U×U/P＝220×220/60≈806.7(Ω)
Power at 220 V: 60 W
Power at 230V:
P＝U×U/R＝230×230/806.7≈65.5(W)
Power at 200V:
P＝U×U/R＝230×230/806.7≈49.6(W)

The focus of the ellipse X212 + Y23 = 1 is F1, and the point P is on the ellipse. If the midpoint m of the line segment Pf1 is on the Y axis, then the ordinate of the point m is ()
A. ±34B. ±32C. ±22D. ±34

Let the coordinate of point p be (m, n). According to the meaning of the title, we can know that the F1 coordinate is (3, 0) ∧ m + 3 = 0 ∧ M = - 3. Substituting it into the elliptic equation, we can get the ordinate of n = ± 32 ∧ m is ± 34, so we choose a

I bought a small power amplifier, only need to output 12v5a power distributor, but now I only have the output power of 18W + 10W multiplied by 2
Same as above
How much V and how much a is 18W + 10W multiplied by 2

Power is not enough, 12v5a is 60W, you'd better go to the electronic market with one, dozens of yuan, but pay attention to the power supply is AC or DC

In order to determine the density of certain metal particles, Li Bing now has a tray balance, a box of weights, an overflow cup and enough water
① Put the balance on the horizontal table and balance it
② Put the metal particles to be measured into the overflow cup filled with water and overflow part of the water. Then use the balance to weigh the total mass M1 of the metal particles, overflow cup and the remaining water
③ Use the balance to weigh the total mass m2 of the overflow cup full of water
④ Weigh the mass m of the metal particle to be measured with a balance
ask
Please write down the expression P for the density of the metal particle to be tested=_____

M overflow = m2-m1
According to P = m / V, v = m overflow / P water
P gold = m gold / V gold, that is p gold = m gold P water / m2-m1

How much power can the battery power supply drive the motor to operate normally?

It is related to the capacity of the storage battery. For example, the storage battery is 12v10ah, the motor is 12v12w, and (current 1a) can run for 10 hours. If the motor power is 24W, it can run for 5 hours. This is only theoretical data. The actual running time is smaller. The larger the capacity of the storage battery is, the longer the normal running time of the motor is

According to the definition of sequence (ε - δ), it is proved that LIM √ n & # 178; + A & # 178 / / N = 1
n→∞

The proof process is as follows: