Question

Оборвется ли в воде канат, выдерживающий вес 50кH, если подымать им со дна реки бетонную плиту масса которой равна 5,5тонн. Плотность бетона = 2300 кг/м³. Помогите СРОЧНО!!!

Answer 1

Дано:
Pmax=50кН=50 000Н
m=5.5т=5500кг
pбетона=2300кг/м3
pводы=1000кг/м3
Решение:
Прежде всего найдем объём V плиты
Есть формула массы m=p*V
Выразим, получаем V=m/p=5500/2300=2.4м3
Найдем силу Архимеда, которая будет действовать на плиту в воде. Именно она "облегчает" плиту
Fарх=ржидкости*Vпогруженной части*g=1000*2.4*10=24 000Н
Найдем силу тяжести плиты
Fтяж=mg=5500*10=55 000Н
Вычтем из силы тяжести силу Архимеда, получим
Fтяж-Fарх=55 000 - 24 000 = 31 000 Н
31 000<50 000, значит канат выдержит

Answer 2

Can a rope holding a weight of 50 kg break if used to lift a concrete slab weighing 5.5 tons from the bottom of a river?

To determine if a rope can withstand the weight of a concrete slab being lifted from the bottom of a river, we need to consider the tension and strength of the rope.

The weight of the concrete slab is given as 5.5 tons, which is equivalent to 5,500 kg. The density of concrete is given as 2,300 kg/m³.

To calculate the volume of the concrete slab, we can use the formula:

Volume = Mass / Density

Plugging in the values, we get:

Volume = 5,500 kg / 2,300 kg/m³

Calculating this, we find that the volume of the concrete slab is approximately 2.39 m³.

Now, let's consider the tension on the rope. The tension in the rope will be equal to the weight of the concrete slab being lifted.

Tension = Weight of Concrete Slab

Tension = 5,500 kg

Given that the rope needs to support a tension of 5,500 kg, we need to determine if the rope is strong enough to handle this load.

Unfortunately, without specific information about the type and strength of the rope, it is difficult to provide a definitive answer. The breaking strength of a rope depends on various factors such as its material, diameter, and construction.

If you have access to the specifications or breaking strength of the rope in question, you can compare it to the tension required to lift the concrete slab. If the breaking strength of the rope is higher than the tension, then the rope should be able to handle the load. However, if the breaking strength is lower than the tension, there is a risk that the rope could break.

It is important to note that lifting heavy objects from the bottom of a river can be dangerous and should be done with proper equipment and expertise. If you are unsure about the safety or feasibility of the operation, it is recommended to consult with professionals or experts in the field.

Please let me know if there is anything else I can help you with!