Sagot :
Answer:
(2) Kinetic energy remains the same and total mechanical energy increases.
Explanation:
A body has kinetic energy due to its speed. A body has potential energy due its position or configuration. The sum of kinetic energy and potential energy is known as mechanical energy.
As the block is pulled up at constant speed, the kinetic energy remains the same. With increase in the height, the potential energy of the body increases. Thus, due to increase in potential energy, there is increase in the total mechanical energy.
Taking into account the definition of kinetic, potencial and mechanical energy, kinetic energy decreases and total mechanical energy remains the same.
Kinetic energy
Kinetic energy is a form of energy. It is defined as the energy associated with bodies that are in motion and this energy depends on the mass and speed of the body.
Kinetic energy is defined as the amount of work necessary to accelerate a body of a given mass and at rest, until it reaches a given speed. Once this point is reached, the amount of accumulated kinetic energy will remain the same unless there is a change in speed or the body returns to its state of rest by applying a force.
Potential energy
On the other hand, potential energy is the energy that measures the ability of a system to perform work based on its position. In other words, this is the energy that a body has at a certain height above the ground.
Gravitational potential energy is the energy associated with the gravitational force. This will depend on the relative height of an object to some reference point, the mass, and the force of gravity.
Mechanical energy
Finally, mechanical energy is that which a body or a system obtains as a result of the speed of its movement or its specific position, and which is capable of producing mechanical work. Then:
Potential energy + kinetic energy = total mechanical energy
Principle of conservation of mechanical energy
The principle of conservation of mechanical energy indicates that the mechanical energy of a body remains constant when all the forces acting on it are conservative (a force is conservative when the work it does on a body depends only on the initial and final points and not the path taken to get from one to the other.)
Therefore, if the potential energy decreases, the kinetic energy will increase. In the same way, if the kinetics decreases, the potential energy will increase.
This case
The principle of conservation of mechanical energy can be applied in this case. When a block is pulled at constant speed up an incline, the potential energy increases because it increases the height.
Then, if by the principle mentioned above, the total mechanical energy remains the same, the kinetic energy decreases.
In summary, the correct answer is option (2) Kinetic energy decreases and total mechanical energy remains the same.
Learn more about mechanical energy:
brainly.com/question/17809741?referrer=searchResults
brainly.com/question/14567080?referrer=searchResults
brainly.com/question/12784057?referrer=searchResults
brainly.com/question/10188030?referrer=searchResults
brainly.com/question/11962904?referrer=searchResults