【判断题】【消耗次数：1】
力的作用线通过矩心时，力矩可能不为零。
①
正确
②
错误
参考答案：
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相关题目
【单选题】
关于力对点之矩的说法，（ ）是错误的。
①
力对点之矩的大小与力的大小有关，而与力的方向无关
②
力对点之矩不会因为力矢沿其作用线移动而改变
③
力的数值为零，或力的作用线通过矩心时，力矩均为零
④
互相平行的两个力，对同一点之矩的代数和为零
【单选题】
关于力对点之矩的说法，（ ）是错误的。
①
力对点之矩的大小与力的大小有关，而与力的方向无关
②
力对点之矩不会因为力矢沿其作用线移动而改变
③
力的数值为零，或力的作用线通过矩心时，力矩均为零
④
互相平行的两个力，对同一点之矩的代数和为零
【单选题】
下列说法中哪个或哪些是正确的（）。 （1）作用在定轴转动刚体上的力越大，刚体转动的角加速度应越大 （2）作用在定轴转动刚体上的合力矩越大，刚体转动的角速度越大 （3）作用在定轴转动刚体上的合力矩为零，刚体转动的角速度为零 （4）作用在定轴转动刚体上合力矩越大，刚体转动的角加速度越大 （5）作用在定轴转动刚体上的合力矩为零，刚体转动的角加速度为零
①
（1）和（2）是正确的
②
（2）和（3）是正确的
③
（3）和（4）是正确的
④
（4）和（5）是正确的
随机题目
【单选题】
What role does a teacher play in the following activity? The teacher asks a student a question “Have you ever bought clothes with problems?” If the student doesn’t seem to be ready, the teacher says “for example, a shirt without...” and points to the buttons on his own shirt or jacket.
①
Controller
②
Assessor
③
Organizer
④
Prompter.
【单选题】
What role does a teacher play in the following activity? T: do you have any hobbies? S: yes, I like singing and dancing. T: Uhm, and...? S: I also collect coins. T: Oh, really, how many...have you already...collected?
①
Controller
②
Assessor
③
Organizer
④
Prompter
【单选题】
Which of the following is the advantage of whole class work?
①
It is an ideal way to show materials and do presentations together
②
It allows students to work together rather than under teacher’s guidance.
③
There is always a great chance of different opinions and contributions to the work
④
It is less stressful.
【单选题】
Which of the following is the time when students work in groups?
①
When all the students are under the control of the teacher
②
When students work in pairs on an exercise or a task
③
When students work in small group
④
When students are expected to work on their own at their own speed.
【单选题】
What role does a teacher play in the following activity? The teacher gives students 2 minutes to skim a text, and when time is up, he asks students to stop and answer some questions.
①
Controller
②
Assessor
③
Organizer
④
Prompter
【单选题】
What are the possible roles of a teacher?
①
Controller, assessor
②
Organizer, prompter
③
Participant, resource-provider
④
All of the above.
【单选题】
Which of the following is the time when students study by themselves?
①
When all the students are under the control of the teacher
②
When students work in pairs on an exercise or a task
③
When students work in small groups
④
When students are expected to work on their own at their own speed.
【单选题】
What role does a teacher play in the following activity? When a student has made a sentence with borrow, “I borrowed a paper to write a letter”, the teacher says, “Well, we don’t say a paper, we say a piece of paper.”
①
Controller
②
Assessor
③
Organizer
④
Prompter.
【单选题】
Why do novice teacher often have problems giving clear instructions?
①
Their language proficiency is low
②
They are fresh from the university
③
Their instructions are too short
④
They are not able to target their instructions to the level of the learners.
【单选题】
When is appropriate for the teacher to give classroom instructions to students?
①
Give directions to tasks or activities, checking comprehension, giving feedback
②
Providing explanations to a concept or language structure, drawing attention
③
Setting requirements, checking comprehension, assigning homework
④
All of the above.