题干

在我们日常生活中,有一种测量人体体重的电子秤,其测量部分的原理如图所示,它主要由压力传感器R(电阻值会随着所受到的压力的大小而发生变化的可变电阻),显示体重大小的仪表A组成,已知压力传感器R的电阻值与所受压力的关系如下表所示.设踏板和压杆的质量忽略不计,接通电源后,压力传感器的两端电压恒为4.8V,请通过计算回答:

压力F/N

0

250

500

750

1000

1250

1500

1750

2000

电阻R/Ω

300

270

240

210

180

150

120

90

60

上一题 下一题 0.0难度 选择题 更新时间:2017-03-03 11:39:45

答案(点此获取答案解析)

同类题2

阅读理解

    Guide to Stockholm University Library

    Our library offers different types of studying places and provides a good studying environment.

    Zones

    The library is divided into different zones. The upper floor is a quiet zone with over a thousand places for silent reading, and places where you can sit and work with your own computer. The reading places consist mostly of tables and chairs. The ground floor is the zone where you can talk. Here you can find sofas and armchairs for group work.

    Computers

    You can use your own computer to connect to the wifi specially prepared for notebook computers; you can also use library computers, which contain the most commonly used applications, such as Microsoft Office. They are situated in the area known as the Experimental Field on the ground floor.

    Group-study Places

    If you want to discuss freely without disturbing others, you can book a study room or sit at a table on the ground floor. Some study rooms are for 2-3 people and others can hold up to 6-8 people. All rooms are marked on the library maps.

    There are 40 group-study rooms that must be booked via the website. To book, you need an active University account and a valid University card. You can use a room three hours per day, nine hours at most per week.

    Storage of study material

    The library has lockers for students to store course literature. When you have obtained at least 40 credits(学分), you may rent a locker and pay 400 SEK for a year's rental period.

    Rules to be followed

    Mobile phone conversations are not permitted anywhere in the library. Keep your phone on silent as if you were in a lecture and exit the library if you need to receive calls.

    Please note that food and fruit are forbidden in the library, but you are allowed to have drinks and sweets with you.