Question

На земле лежит бревно, торцы бревна имеют разные диаметры. Объем бревна = 0,2 м3, средняя плотность 450 кг/м3. Чтобы поднять один край бревна необходима сила F1=350 Н. Найти силу F2, которую необходимо приложить, чтобы приподнять второй край.

Answer 1

M=ро* V=90кг
F=mg=90*10=900H
F2=F-F1=900-350=550H

Answer 2

Given Information:

- Volume of the log: 0.2 m^3 - Average density of the log: 450 kg/m^3 - Force required to lift one end of the log (F1): 350 N

Calculating the Mass of the Log:

To find the mass of the log, we can use the formula:

Mass = Density x Volume

Substituting the given values:

Mass = 450 kg/m^3 x 0.2 m^3

Calculating the mass:

Mass = 90 kg

Calculating the Force Required to Lift the Other End (F2):

To find the force required to lift the other end of the log (F2), we can use the principle of moments. The principle of moments states that the sum of the clockwise moments is equal to the sum of the anticlockwise moments.

In this case, the clockwise moment is the force F1 multiplied by the distance from the center of the log to the end, and the anticlockwise moment is the force F2 multiplied by the distance from the center of the log to the other end.

Since the torques are equal, we can set up the equation:

F1 x d1 = F2 x d2

Where: - F1 is the force required to lift one end of the log (350 N) - d1 is the distance from the center of the log to the end (unknown) - F2 is the force required to lift the other end of the log (unknown) - d2 is the distance from the center of the log to the other end (unknown)

We can rearrange the equation to solve for F2:

F2 = (F1 x d1) / d2

To find the values of d1 and d2, we need to know the diameters of the log's ends. Unfortunately, the diameters of the log's ends are not provided in the given information. Therefore, we cannot calculate the force required to lift the other end (F2) without this information.

Please provide the diameters of the log's ends so that we can proceed with the calculation.