Question

Кирпич высотой 8 см, шириной 15 см, длиной 25 см имеет массу 2 кг. Какое давление оказывает кирпич на пол, находясь в трёх различных положениях?

Answer 1

P=F/S. F=mg. S=ab
1)высота и ширина p=2·10/0,8·0,15=167 Па
2)высота и длина p=20/0,8·0,25=100Па
3)длина и ширина p=20/0,25·0,15=533Па

Answer 2

Calculation of Pressure Exerted by the Brick

To calculate the pressure exerted by the brick on the floor in three different positions, we need to use the formula for pressure:

Pressure = Force / Area

In this case, the force is the weight of the brick, and the area is the contact area between the brick and the floor.

Position 1: Brick Standing on its Longest Side

In this position, the brick is standing on its longest side, with dimensions of 25 cm (length) x 15 cm (width) x 8 cm (height).

To calculate the contact area, we need to consider the area of the base of the brick, which is the length multiplied by the width:

Area = Length x Width = 25 cm x 15 cm = 375 cm²

The weight of the brick is given as 2 kg.

To convert the weight to force, we need to multiply it by the acceleration due to gravity, which is approximately 9.8 m/s².

Force = Weight x Acceleration due to Gravity = 2 kg x 9.8 m/s² = 19.6 N

Now we can calculate the pressure:

Pressure = Force / Area = 19.6 N / 375 cm²

To convert the area from cm² to m², we divide by 10,000:

Pressure = 19.6 N / (375 cm² / 10,000) = 19.6 N / 0.0375 m²

Calculating this, we find that the pressure exerted by the brick on the floor in this position is approximately 522.67 Pa.

Position 2: Brick Standing on its Shortest Side

In this position, the brick is standing on its shortest side, with dimensions of 8 cm (length) x 15 cm (width) x 25 cm (height).

The contact area is still the same, as it is determined by the base of the brick:

Area = Length x Width = 8 cm x 15 cm = 120 cm²

The weight of the brick remains the same at 2 kg.

Using the same calculations as before, we find that the pressure exerted by the brick on the floor in this position is also approximately 522.67 Pa.

Position 3: Brick Lying Flat on its Longest Side

In this position, the brick is lying flat on its longest side, with dimensions of 25 cm (length) x 8 cm (width) x 15 cm (height).

The contact area is now the area of the longest side of the brick:

Area = Width x Height = 8 cm x 15 cm = 120 cm²

The weight of the brick remains the same at 2 kg.

Using the same calculations as before, we find that the pressure exerted by the brick on the floor in this position is also approximately 522.67 Pa.

Summary

In all three positions, the pressure exerted by the brick on the floor is approximately 522.67 Pa.

Please note that the calculations provided are based on the given dimensions and weight of the brick.