Question

Помогите пожалуйста!!!Определить работу силы тяжести при подъёме портфеля.

Answer 1

Understanding the Question

You are asking about the work done by the force of gravity when lifting a backpack.

Work Done by the Force of Gravity

When lifting an object, such as a backpack, the force of gravity is acting on it. The work done by the force of gravity can be calculated using the formula:

Work = Force x Distance x cos(θ)

Where: - Work is the work done by the force of gravity (measured in joules, J) - Force is the force of gravity acting on the object (measured in newtons, N) - Distance is the vertical distance over which the object is lifted (measured in meters, m) - θ is the angle between the force of gravity and the direction of motion (in this case, the angle is 0 degrees since the force of gravity acts vertically downwards)

Since the force of gravity is acting vertically downwards and the object is being lifted vertically upwards, the angle between the force of gravity and the direction of motion is 0 degrees. Therefore, the cosine of 0 degrees is 1, and the formula simplifies to:

Work = Force x Distance

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

Weight = Mass x Acceleration due to gravity

Where: - Weight is the force of gravity acting on the object (measured in newtons, N) - Mass is the mass of the object (measured in kilograms, kg) - Acceleration due to gravity is the acceleration experienced by objects near the surface of the Earth, which is approximately 9.8 m/s^2

Therefore, the work done by the force of gravity when lifting a backpack can be calculated by multiplying the weight of the backpack by the vertical distance over which it is lifted.

Example Calculation

Let's say the mass of the backpack is 5 kilograms and it is lifted vertically upwards by a distance of 2 meters. The work done by the force of gravity can be calculated as follows:

1. Calculate the weight of the backpack: Weight = Mass x Acceleration due to gravity Weight = 5 kg x 9.8 m/s^2 = 49 N

2. Calculate the work done by the force of gravity: Work = Force x Distance Work = 49 N x 2 m = 98 J

Therefore, the work done by the force of gravity when lifting the backpack is 98 joules.

Conclusion

The work done by the force of gravity when lifting a backpack can be calculated by multiplying the weight of the backpack by the vertical distance over which it is lifted. In the example provided, the work done was calculated to be 98 joules.