Question

Помогите решить.В установке изображенной на рисунке, грузик A соединен перевернутой через блок нитью с бруском B, лежащим на горизонтальной поверхности трибометра, закрепленного на столе. Грузик отводят в сторону, приподнимая его на высоту h и опускают. Длина свисающей части нити равна L. Какую величину должна превзойти масса грузика чтобы брусок сдвинулся с места в момент прохождения грузиком нижней точки траектории? Масса бруска М, коэффициент трения между бруском и поверхностью фи. Трением в блоке и размерами блока пренебречь

Answer 1

быстро решите да попрацки срочноо надо плиииииззз

 

Answer 2

To solve this problem, we need to consider the forces acting on the block B when the weight A is lifted and lowered. The block B will start moving when the force of friction between the block and the surface exceeds the maximum static friction force.

Forces Acting on Block B:

1. Weight of block B: This force acts vertically downwards and is equal to the product of the mass of block B (M) and the acceleration due to gravity (g). 2. Normal force: This force acts perpendicular to the surface of the tribometer and is equal to the weight of block B. 3. Force of friction: This force acts parallel to the surface of the tribometer and opposes the motion of block B. It is given by the product of the coefficient of friction (μ) and the normal force.

Conditions for Block B to Start Moving:

For block B to start moving, the force of friction must exceed the maximum static friction force. The maximum static friction force is given by the product of the coefficient of static friction (μs) and the normal force.

Calculation:

Let's assume that the mass of weight A is m and the tension in the string is T.

When the weight A is lifted, the tension in the string is equal to the weight of A: T = m * g

When the weight A is lowered, the tension in the string is equal to the weight of A plus the weight of block B: T = (m + M) * g

The force of friction between block B and the surface is equal to the tension in the string: F_friction = T

To find the condition for block B to start moving, we need to compare the force of friction with the maximum static friction force: F_friction > μs * (M * g)

Substituting the value of T, we get: (m + M) * g > μs * (M * g)

Simplifying the equation, we find: m > μs * M

Therefore, the mass of weight A should be greater than the product of the coefficient of static friction (μs) and the mass of block B (M) for block B to start moving.

Please note that the given problem does not provide the values of μs, M, or any other specific quantities. Therefore, we cannot provide a numerical answer without these values.