题干

随着经济发展,人们生活水平的逐渐提高,扫地机器人逐步进入普通家庭.扫地机器人具有主动躲避障碍物、自动吸尘、自动返回充电座充电等诸多智能功能.如图是某款扫地机器人及铭牌上的部分参数,请回答下列有关问题:

(1)机器人吸尘的工作原理是什么,从而使杂物进入吸尘器.

(2)电池容量“2000mAh”是指当工作电流为2000mA,能持续供电1小时.若充满电后所有电量用于扫地,则可供机器人持续正常工作多少时间?

(3)机器人的供电系统设有自动充电功能,当检测到电池容量低至10%时会自动返回充电.若返回过程中受到的阻力为20N,为确保机器人能顺利返回充电,需要充电时离充电座最远为多少米?(剩余电池容量的40%用于提供克服阻力做功)

项目

指标参数

工作电压

15V

功率

30W

电池容量

2000mAh

上一题 下一题 0.0难度 选择题 更新时间:2019-07-05 02:31:53

答案(点此获取答案解析)

解:(1)高速旋转的叶轮把空气排出风机,同时使外部空气和灰尘不断地补充进风机,吸尘器就能“吸尘”了,其原理利用了流体流速大的地方压强小.
(2)电池的容量为W=UIt=15V×2A×3600s=108000J,
由P=
W
t
得:
t=

同类题1

阅读下面短文,从每小题所给的A、B、C、D四个选项中选出最佳选项。

B

    Everyone wants to have a perfect life. But how can we own that? The writer called Brian Tracy tells us some tips:   

    The first goal common to all of us is healthy and energy. We all want to be healthy and fit, to have high levels of energy and to live free of pain and illness. Today, with the quick development of medical science, the quality of our health and fitness, and our lifespan(寿命), is largely determined by design, not by chance. People with excellent health habits are far healthier, have more energy, and live longer and better than people who have poor health habits.

    The second goal that we all have in common is to enjoy excellent relationships, getting along well with the people we like and respect, and who like, love and respect us in turn. Fully 85% of your happiness will be determined by the quality of your relationships(人际关系) at each time, and in each area, of your life. How well you get along with people, and how much they like, love and respect you, has more effect on the quality of your life than perhaps any other reasons.

    The third common goal is to do work that we enjoy, to do it well, and to be well paid for it. You want to be able to get and keep the job you want, to get paid more and promoted(提升) faster. You want to earn as much money as possible at any time, whatever you do.

    The last goal we all have in common is to reach the point in life where you have enough money so that you never have to worry about money again. You want to be completely free of worries about money.