一个塑料瓶装有500ml水，则所装水的质量为______g，把它放置在太阳底下1小时后，水温由10℃升至30℃，水吸收的热量为______J．
∵V=500ml=500cm3，ρ=1g/cm3，
∴所装水的质量为：m=ρV=1g/cm3×500cm3=500g=0.5kg，
而C=4.2×103J/（kg•℃），△t=t-t0=30℃-10℃=20℃，
∴水吸收的热量为：Q吸=Cm△t=4.2×103J/（kg•℃）×0.5kg×20℃=4.2×104J．
故答案为：500，4.2×104．
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| There are four seasons in a year. They are spring, summer, fall and winter. 1________ is the first season of the year. It is getting 2________ and flowers begin to open. Trees and grass begin to turn 3________. It's usually rainy, people like to fly kites. Then it is summer and it is the 4________ season of the year. The days get 5________, so we can play in the afternoon. 6________ is the third season. It's very beautiful. It's not too hot and not too cold. There is usually 7________ in fall and leaves begin to turn yellow and come down. Many people like to have a picnic in the park. The last season of the year is winter. People usually don't like to go 8________ because it is cold. And there is sometimes 9________ in winter. Then we play with it. But it is the 10________ of the year. So we have to wear heavy clothes such as winter jacket in winter.
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