( 1)V = 2.5l = 2.5× 10-3m 3？

According to the formula, the mass of this pot of water is obtained.

M = rho water V =1.0×103 kg/m3× 2.5×10-3 m3 = 2.5 kg;

(2) The heat required to boil this pot of water.

Q absorption = cm (t-t0) = 4.2×103j/(kg℃ )× 2.5 kg× (100℃-20℃) = 8.4×105j;

(3) If all the electric energy consumed when boiling water is absorbed by water, then

W=Q suction =8.4× 10 5 J

From the formula P=, it is = 1200 s=20 min.

That is to say, according to the advertising power of the electric kettle, it takes at least 20 minutes to boil this pot of water, and it is impossible to boil a pot of water in about 5 minutes. It can be seen that the content of publicity advertisements is not credible;

(4) the power of the electric kettle. Because the volume and boiling time of the kettle can be accurately judged according to people's life experience, it is not convenient to measure directly because they are not familiar with the power of the electric kettle.