1.Un conductor este străbătut de un curent electric cu I = 1.

The body weighing 2 kg moves through the horizontal surface and crosses the path x = 75 cm The coefficient of friction of the bo

Taya2010 [7]

The kinetic energy of the body in definitive position is 4.24 J.

Explanation:

As per the work energy theorem, the work done on any system or object to move it from one position to another is equal to the change in kinetic energy of the object. In this case, the body weighing 2 kg is moved over an horizontal surface for a distance of 75 cm. As there will be frictional force acting on the body while moving over the surface. This frictional force multiplied by the distance the object is moved will give the work done on the body.

Frictional force = Coeffficent of friction × Normal force.

As the weight of the body is 2 kg, the normal force acting on it will be mass multiplied with acceleration due to gravity.

Frictional force = - 0.8×9.8 × 2 =-15.68 N

So the work done will be the product of frictional force with the displacement of 75 cm or 0.75 m.

Work done = Frictional force × Displacement

Work done = -15.68×0.75 = -11.76 J.

So the work is done by the object.

If the kinetic energy of the body at starting is 16 J, then the kinetic energy of the body at definitive position will be obtained as below.

Work done = change in kinetic energy

-11.76 J = Final kinetic energy-16 J

Final Kinetic energy = - 11.76+16

Final kinetic energy = 4.24 J

Thus, the kinetic energy of the body in definitive position is 4.24 J.

3 0

3 years ago

BI

Charra [1.4K]

Answer: A

Explanation:

8 0

3 years ago

ECONOMICS GRADE 10 CASE STUDY TOPIC: South African growth and development: Mining and industry Manufacturing and services.

bearhunter [10]

The correct answe is South Africa - Economic Growth and Development:

After the formal end of the previous apartheid system two decades ago, South Africa can now boast having one of the richest economies in Africa and a well-functioning democracy. It is the largest economy in Africa, but it also has deeply ingrained structural issues that limit its ability to expand and flourish.

One of the largest economies on the African continent is that of South Africa. However, despite a period of rapid development from 2003 to 2007, its real GDP average yearly growth rate between 2001 and 2010 has been very weak and unquestionably significantly below the African average. A number of African nations have had substantially faster growth rates, which has improved a number of development-related indices.

By the standards of the recent growth records of several Euro Zone nations, South Africa's development is hardly sluggish! One crucial aspect of the economy is that South Africa has achieved relatively modest progress in meeting a number of important development targets and some of the Millennium Development Goals, but her economy does not appear to have achieved the "take-off" required to kick start significant development progress, especially against the backdrop of her deep social problems.

To learn more about South Africa's development refer the link:

brainly.com/question/24400106

#SPJ9

6 0

2 years ago

Because of interstellar dust, astronomers can see at most about 5 kpc into the disk of the galaxy at visual wavelengths. What pe

NNADVOKAT [17]

Answer:

96%

Explanation

Let A the total area of the galaxy, is modeled as a disc:

A = πR^2 = π (25 kpc)^2

And let a be the area that astronomers are able to see:

a = πr^2 = π(5 kpc)^2

The percentage that can be seen is equal to 100 times the ratio of the areas, of the galaxy and the "visible" part:

P = 100 a/A = (5/25)^2 = 100/25 = 4%

Therefore, the percentage of the galaxy not included, i.e. not seen is:

(100-4)% = 96%

5 0

3 years ago

Which type of surface would most likely be the best reflector of electromagnetic energy?

Len [333]

<span>light colored and smooth surface would most likely be the best reflector of electromagnetic energy.Light, shiny surfaces are the best reflectors of radiation and they will allow the waves to reflect and bounce off rather than absorb. we can consider mirror as the example ,it will only reflect the light energy falling on them and it will not absorb. The darker coloured and rough surfaced substances will definitely absorb some amount of light falling on it. so light coloured smooth or shiny surfaced material would be the best reflector for electromagnetic energy.</span>

5 0

3 years ago