The ice on the lake can withstand a pressure of 30 kPa. A man with an area of the sole of his boots 400 cm2

| June 9, 2021 | education

The ice on the lake can withstand a pressure of 30 kPa. A man with an area of the sole of his boots 400 cm2 stands on the surface of the ice. What is the maximum mass a person can have so that the ice under him does not collapse?

To find out the maximum mass of the specified person, consider the inequality: Rl ≥ Rh; Rl ≥ mh * g / Sb, whence we express: mh ≤ Rl * Sb / g.

Const: g – acceleration due to gravity (according to the condition g ≈ 10 m / s2).

Data: Рл – pressure maintained by ice (Рл = 30 kPa = 3 * 10 ^ 4 Pa); Sb – the total area of the boots, support (Sb = 400 cm2, in the SI system Sb = 4 * 10 ^ -2 m2).

Let’s calculate: mh ≤ Rl * Sb / g.

mh ≤ 3 * 10 ^ 4 * 4 * 10 ^ -2 / 10.

mh ≤ 120 kg.

Answer: The maximum weight of the specified person is 120 kg.



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