Question

СРОЧНО ПОЖАЛУЙСТА ПОМОГИТЕ Строитель, подняв ящик массой 10 кг с пола на высоту 1 м, пере-носит его, не изменяя высоты, на расстояние 1000 см и опускаетна пол. Определите работу силы тяжести на каждом этапе и полнуюработу. ​

Answer 1

Ответ:

ответ прикреплен на фото

Answer 2

Problem Analysis

The problem involves a builder lifting a box with a mass of 10 kg from the floor to a height of 1 m, then carrying it horizontally for a distance of 1000 cm, and finally lowering it back to the floor. We need to determine the work done by the force of gravity at each stage and the total work done.

Solution

To solve this problem, we need to calculate the work done by the force of gravity at each stage and then sum them up to find the total work done.

1. Lifting the box from the floor to a height of 1 m: - The work done by the force of gravity can be calculated using the formula: work = force x distance x cos(theta), where theta is the angle between the force and the displacement. - In this case, the force of gravity is acting vertically downward, and the displacement is vertical as well. Therefore, the angle between the force and the displacement is 0 degrees, and cos(0) = 1. - The work done by the force of gravity is given by: work = force x distance x cos(0) = m x g x h, where m is the mass of the box, g is the acceleration due to gravity, and h is the height. - Substituting the given values: work = 10 kg x 9.8 m/s^2 x 1 m = 98 J.

2. Carrying the box horizontally for a distance of 1000 cm: - Since the box is being carried horizontally, the force of gravity does not do any work during this stage. This is because the force of gravity is acting vertically downward, while the displacement is horizontal. The angle between the force and the displacement is 90 degrees, and cos(90) = 0. - Therefore, the work done by the force of gravity during this stage is 0 J.

3. Lowering the box from a height of 1 m back to the floor: - Similar to the first stage, the work done by the force of gravity can be calculated using the formula: work = force x distance x cos(theta). - The force of gravity is acting vertically downward, and the displacement is vertical as well. Therefore, the angle between the force and the displacement is 0 degrees, and cos(0) = 1. - The work done by the force of gravity is given by: work = force x distance x cos(0) = m x g x h. - Substituting the given values: work = 10 kg x 9.8 m/s^2 x 1 m = 98 J.

Summary

To summarize, the work done by the force of gravity at each stage is as follows: - Lifting the box from the floor to a height of 1 m: 98 J - Carrying the box horizontally for a distance of 1000 cm: 0 J - Lowering the box from a height of 1 m back to the floor: 98 J

The total work done by the force of gravity is the sum of the work done at each stage: 98 J + 0 J + 98 J = 196 J.

Please note that the above calculations assume that the force of gravity is the only force acting on the box during each stage and that there is no loss of energy due to friction or other factors.