Question

Подъёмный кран переносит в горизонтальной плоскости груз массой 15 кг на расстояние 12 м, потом поднимает этот груз на высоту 22 м. Вычислите работу, совершаемую силой тяжести на каждом этапе.​

Answer 1

Ответ: 5,1кДж

Объяснение:

Дано:

m=15кг

S=12м

h=22м

g=10Н/кг

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А-?

А=mg(S+h)=15*10*(12+22)=5100Дж=5,1кДж

Answer 2

Calculation of Work Done by Gravity

To calculate the work done by the force of gravity at each stage, we need to consider the horizontal displacement and the vertical displacement separately.

Stage 1: Horizontal Displacement

The crane moves the load horizontally for a distance of 12 m. The mass of the load is 15 kg.

The work done by the force of gravity during the horizontal displacement is zero. This is because the force of gravity acts vertically downwards, while the displacement is horizontal. The angle between the force of gravity and the displacement is 90 degrees, resulting in zero work done.

Stage 2: Vertical Displacement

The crane then lifts the load vertically to a height of 22 m.

The work done by the force of gravity during the vertical displacement can be calculated using the formula:

Work = Force x Displacement x cos(theta)

In this case, the force of gravity is equal to the weight of the load, which can be calculated using the formula:

Weight = mass x acceleration due to gravity

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

Let's calculate the work done during the vertical displacement:

Weight = 15 kg x 9.8 m/s^2 = 147 N

Work = 147 N x 22 m x cos(180 degrees) = -3234 J

The negative sign indicates that the work done by the force of gravity is in the opposite direction of the displacement.

Therefore, the work done by the force of gravity during the vertical displacement is -3234 Joules.

To summarize:

- Work done by the force of gravity during the horizontal displacement: 0 J - Work done by the force of gravity during the vertical displacement: -3234 J

Please note that the calculations provided are based on the given information and assumptions.