名校
1 . 某种型号的电热水器工作过程如下:在接通电源以后,从初始温度20
下加热水箱中的水,当水温达到设定温度60
时,加热停止;此后水箱中的水温开始逐渐下降,当下降到保温温度30
时,再次自动加热水箱中的水至60
,加热停止;当水箱中的水温下降到30
时,再次自动加热,……,按照以上方式不断循环.小宇根据学习函数的经验,对该型号电热水器水箱中的水温随时间变化的规律进行了探究,发现水温
是时间
的函数,其中
(单位:
)表示水箱中水的温度,
(单位:
)表示接通电源后的时间.下面是小宇的探究过程,请补充完整:
(1)小宇记录了从初始温度20
第一次加热至设定温度60
,之后水温冷却至保温温度30
的过程中,
随
的变化情况,如下表所示:
①请写出一个符合加热阶段
与
关系的函数解析式______________;
②根据该电热水器的工作特点,当第二次加热至设定温度60
时,距离接通电源的时间
为________
.
(2)根据上述的表格,小宇画出了当
时的函数图象,请根据该电热水器的工作特点,帮他画出当
时的函数图象.
![](https://img.xkw.com/dksih/QBM/2020/4/21/2446230314352640/2446961010761728/STEM/30d44c97e69d46e7b6740877a0d3f9b2.png?resizew=375)
(3)已知适宜人体沐浴的水温约为
,小宇在上午8点整接通电源,水箱中水温为20
,热水器开始按上述模式工作,若不考虑其他因素的影响,请问在上午9点30分时,热水器的水温______(填“是”或“否”)适合他沐浴,理由是_________________.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11481dcf3bb5f472762e08bab4194cf4.png)
(1)小宇记录了从初始温度20
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
接通电源后的时间![]() ![]() | 0 | 2 | 4 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | … |
水箱中水的温度![]() ![]() | 20 | 30 | 40 | 60 | 51 | 45 | 40 | 36 | 33 | 30 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
②根据该电热水器的工作特点,当第二次加热至设定温度60
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11481dcf3bb5f472762e08bab4194cf4.png)
(2)根据上述的表格,小宇画出了当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fd029f6eb105ea3011e815d40020c45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5d309a545ae8fd291c4a79e6b513b84.png)
![](https://img.xkw.com/dksih/QBM/2020/4/21/2446230314352640/2446961010761728/STEM/30d44c97e69d46e7b6740877a0d3f9b2.png?resizew=375)
(3)已知适宜人体沐浴的水温约为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4279e8afcd4b0ab497d36c195b34ddd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de96374212b9a5df820d78d10e7d1291.png)
您最近一年使用:0次