What time units, seconds and hours are used to calculate electric power

What time units, seconds and hours are used to calculate electric power

Formula: P = w / T
In the formula, W is in joules, t is in seconds, and the unit of result P should be w (Watts)
In the formula, the unit of W is kilowatt hour, the unit of time t is hour, and the unit of result P should be kW (kilowatt)

Can we calculate the electrical work hour (w = UIT) in hours?

No, it has to be seconds

Connect an electric furnace wire with a resistance of 484 Ω to the lighting circuit, and when it is energized for 240s, it will be discharged______ If we cut off half the length of the electric furnace wire and connect the remaining part to the lighting circuit, it will release the same amount of heat, and the power on time is______ s．

(1) ∵ q = i2rt, I = ur, u = 220V, r = 484 Ω ∵ q = u2rt = (220V) 2484 Ω × 240s = 2.4 × 104j; (2) if half the length of the furnace wire is cut off, the resistance of the remaining part is R '= 12R = 12 × 484 Ω = 242 Ω, ∵ q = u2rt ∵ t = QR ′ U2 = 2.4 × 104j × 242 Ω (220V) 2 = 120s

Physical electric power
1、 Zhang Ke recently noticed that the light bulb in his home is brighter than usual. He guessed that the voltage may be more than 250V. In order to verify his conjecture, he made an experiment. He turned off all electrical appliances in his home and turned on only one "220V 100W" light. The energy meter marked "3000r, kW ` H" in the observer turned 121 turns in 20min
1. The resistance of this bulb
2. The energy consumed by this lamp in 20 minutes
3. What is the actual point of Zhang Kejia at this time
4. In order to make the bulb shine normally, what resistance should be connected in series
2、 The resistance value of R1 is 10 Ω, and the word "6V" can be seen clearly on the bulb name plate. When the switch is closed, the indication of ammeter is 2A. When the switch section starts, the indication of voltmeter is 6V, what is the rated electric power of the small bulb? (the ammeter is in the trunk circuit, the voltmeter measures the voltage at both ends of the small bulb, and the switch is in parallel with the small bulb.)
3、 Xiaoming's electric energy meter is marked with the words "600r / kW / h". If there is only one electrical appliance in her family working, and the turntable rotates for 60 minutes, what is the energy consumed by this electrical appliance during this period? What is the power of this electrical appliance?
(requirements:

I 1. R = u ^ 2 / P = 220 * 220 / 100 = 484 Ω 2. W = 121 / 3000 = 0.0403kw ` H = 145200w3. W = u ^ 2 * t / R, u = 242v4. Normal lighting, resistance R partial voltage 242-220 = 22V, current I = 100 / 220ar = 22 / (5 / 11) = 48.4 Ω, two power supply u = 2 * 10 = 20V, current I = (20-6) / 10 = 1.4A, rated power P = UI =