Elementary school math problems mechanics mechanics problems.

You misunderstood.

There are pig heads, taro, dog heads, and cats sold in the vegetable market. I buy taro, dog head. You buy 3 kinds of chicken heads, duck heads, and taro. Did you and I both buy 3 of them? Note"Common"!!!

Because it is necessary to count the least common and correct ones. The total number of topics should be taken into account. The least common multiple of 3 and 5 is 15, so A gets 5 questions wrong and B gets 7 questions.

Same as 3 wrong questions. There are another 7+5-3*2=6 questions, which are miscalculated for a total of 12 questions. So the same is 15-12 = 3 questions.

So at least 3 questions are counted correctly.

Note: If it is an answer question, it should be considered.

General form (more annoying, I don't bother to say).

It's impossible, probably because you're making a mistake with your question.

If A gets one-third of all the questions wrong, then A and B can't get one-fifth of the total number of questions. So, it's your fault!

There are three possibilities:

1.Your question is wrong.

2.You made a mistake while typing.

3.It's a technical problem for all of us

7 (A gets a few points wrong in the total) one-fifth - one-third multiplied by the difference between the quotient of one divided by two = the number of questions in a paper, i.e. 210 questions.

210*(1-fifth)-7=161 questions.

Note: The questions that A and B get wrong together account for one-fifth of the total number of questions.

If A gets one-third of all the questions wrong, then A and B can't make one-fifth of the total number of questions, and there is a problem with the question.

What A and B are wrong together is a question that both people are wrong, not two people who are wrong.

It can't be, at least a third.

The monoatomic ideal gas CV=3R2, CP=5R2 is definite and can be brought in directly.

True or False Contact does not mean that there is an interaction force on the contact surfaceWrong The acting force and the reaction force act on different objects, and only the forces acting on the same object can cancel each other out.

Can't see correctly.

True (the chain rod is not subject to moments, it may experience multiple forces at the node at the same time, but its intrinsic property is only tension when balanced).

False The resultant force is the vector sum of the component forces, if the two components are equal to each other, then the absolute value of the resultant force is 0; Smaller than both components.

In the tensile (compression) test, in the elastic deformation stage, the stress is proportional to the strain, and the slope of the straight line is: tg e, which can be written as e, which is Hooke's law. where — stress (mpa), strain (unitless), e - tensile (compressive) modulus of elasticity (mpa) of the material.

Hooke's law is expressed in another form: δl n l) (e a), where δl - the longitudinal absolute deformation of the tension (compression) rod (mm), n - axial force (n), a - cross-sectional area (mm), l - rod length (mm). Some books refer to the formula δl n l) (e a) as Hooke's law, and e as another expression.

Twenty-five, the red dust is flashy and flashy.

With these two conditions, it can be obtained:

Common point force balance: n1+n2=w.........1）

The following point is the axis, and the moment is 0: h * b + n1 * a = w * a 2 ......（2）

The above point is the axis, and the moment is 0 to obtain: w * a 2 + h * b = n2 * a ......（3）

From above: ......