Fortune-telling: Xin Li blood type A 1985, 1.20, 15, from Luoyang, Henan.

Are all junior high school students here?

The first question: just use 1250W*8*3600S*56% heat absorption power. If your question is correct, so be it. If the heat absorption power refers to heat absorption per second per square meter, it is still *2.

It represents the energy that can be effectively used when the efficiency is 56% after water absorbs heat for 8 hours at this power.

Q=Cm(t-t0) can be used to calculate the second question, and Q is the answer to the first question. C is 4.2 * 10 3J/(kg. C ℃) M is the mass of 160 liters of water, 160 kg. T is the required temperature, and T0 is 5℃.

The third question is more difficult. First, calculate the heat required for 160 kg of water to rise to 45℃, and the formula used is still Q=Cm(t-t0). But this time q is unknown, t is 45℃, t0 is 5℃.

Then use Q=W=Pt to find the time.

P is 2000W

Give it a try!