Question

Мальчик массой 60 кг воткнул в землю лопату и встал на нее . определите давление лопаты на почву,если ширина лопаты 20 см , а толщина острия 0,6мм.массу лопаты не учитывать .

Answer 1

Дано:
m=60кг
b=20см
толщина=0,6мм
СИ:
0,2м
0,006м
Решение:
Fтяж=mg
Fтяж=60кг*10н/кг=600н
S=ab
S=0,2м*0,006м=0,0012м²
p=F/S
p=600н/0,0012м²=500000н/м²=500000Па=500кПа

Answer 2

Calculation of Pressure

To determine the pressure exerted by the shovel on the ground, we need to divide the force exerted by the shovel by the area over which the force is distributed. In this case, the force exerted by the shovel is equal to the weight of the boy standing on it.

Given: - Mass of the boy = 60 kg

To calculate the force exerted by the boy, we can use the formula:

Force = Mass x Acceleration due to gravity

The acceleration due to gravity is approximately 9.8 m/s^2.

Using this formula, we can calculate the force exerted by the boy:

Force = 60 kg x 9.8 m/s^2

Now, we need to calculate the area over which the force is distributed. The area can be calculated by multiplying the width of the shovel by the thickness of the blade.

Given: - Width of the shovel = 20 cm = 0.2 m - Thickness of the blade = 0.6 mm = 0.0006 m

To calculate the area, we can use the formula:

Area = Width x Thickness

Using this formula, we can calculate the area:

Area = 0.2 m x 0.0006 m

Now, we can calculate the pressure exerted by the shovel on the ground by dividing the force by the area:

Pressure = Force / Area

Let's calculate the values:

Force = 60 kg x 9.8 m/s^2 = 588 N Area = 0.2 m x 0.0006 m = 0.00012 m^2

Pressure = 588 N / 0.00012 m^2

Therefore, the pressure exerted by the shovel on the ground is 4,900,000 N/m^2.

Please note that this calculation assumes that the weight of the shovel is negligible compared to the weight of the boy and does not affect the pressure calculation.