Question

Размеры кирпича равны 25 см x 13 см x 7 см. Масса кирпича — 9,9 кг. Какое наибольшее и наименьшее давление оказывает кирпич при строительстве стены? Результат округли до единиц. Принять g≈10Н/кг.

Answer 1

Ответ:

P= F/S = mg/S = 9.9*10/S = 99/S

$S_{min}$ = 0.13 *0.07 = 0.0091

$S_{max}$ = 0.25 * 0.13 = 0.0325

P = 99/0.0091 = 10 879 Па - это наибольшее

P = 99/0.0325 = 3 046 Па  - это наименьшее

Answer 2

Calculating the Maximum and Minimum Pressure Exerted by the Brick

To calculate the maximum and minimum pressure exerted by the brick during wall construction, we need to consider the dimensions and mass of the brick.

Given: - Dimensions of the brick: 25 cm x 13 cm x 7 cm - Mass of the brick: 9.9 kg - Acceleration due to gravity (g): approximately 10 N/kg

To calculate the maximum pressure, we need to find the smallest face of the brick, as the pressure is inversely proportional to the area of contact. The smallest face of the brick is the one with dimensions 7 cm x 13 cm.

To calculate the minimum pressure, we need to find the largest face of the brick, as the pressure is inversely proportional to the area of contact. The largest face of the brick is the one with dimensions 25 cm x 13 cm.

Now, let's calculate the maximum and minimum pressures exerted by the brick.

Calculating the Maximum Pressure:

To calculate the maximum pressure, we need to divide the weight of the brick by the area of the smallest face.

Weight of the brick = mass x acceleration due to gravity Weight of the brick = 9.9 kg x 10 N/kg Weight of the brick = 99 N

Area of the smallest face = length x width Area of the smallest face = 7 cm x 13 cm Area of the smallest face = 91 cm²

Maximum pressure = weight of the brick / area of the smallest face Maximum pressure = 99 N / 91 cm²

Converting cm² to m²: 1 cm² = 0.0001 m²

Maximum pressure = 99 N / (91 cm² x 0.0001 m²) Maximum pressure = 99 N / 0.0091 m² Maximum pressure ≈ 10879.12 N/m²

Rounding the result to the nearest unit, the maximum pressure exerted by the brick during wall construction is approximately 10879 N/m².

Calculating the Minimum Pressure:

To calculate the minimum pressure, we need to divide the weight of the brick by the area of the largest face.

Weight of the brick = 99 N (as calculated earlier)

Area of the largest face = length x width Area of the largest face = 25 cm x 13 cm Area of the largest face = 325 cm²

Minimum pressure = weight of the brick / area of the largest face Minimum pressure = 99 N / 325 cm²

Converting cm² to m²: 1 cm² = 0.0001 m²

Minimum pressure = 99 N / (325 cm² x 0.0001 m²) Minimum pressure = 99 N / 0.0325 m² Minimum pressure ≈ 3046.15 N/m²

Rounding the result to the nearest unit, the minimum pressure exerted by the brick during wall construction is approximately 3046 N/m².

Please note that these calculations assume the weight of the brick is evenly distributed across the contact area.