Is there a person doing work when taking the elevator?

How could there not be?

In terms of the definition of work:

Work = component force in the direction of displacement * displacement, a person steps on the elevator and exerts a vertical downward force on the elevator, and the elevator has displacement in this direction, so it does work. The elevator is doing negative work upwards and positive work when it is downward.

In terms of the relationship between function and energy:

People do work on the elevator and transfer energy to the elevator, which will make the elevator show a change in energy. As an example, many elevators now use energy feedback technology, and in some cases, the elevator not only does not consume electricity, but also generates electricity and feeds it back to the grid. In this case, the feedback electrical energy, which is the work done by people, becomes mechanical energy, and then becomes electrical energy from the elevator drive system.

If people don't do work, the theorem of conservation of energy will have to be rewritten.

Conclusion: Those who do work, go up to do negative work, and go down to do positive work.

What kind of elevator did you score?

If it is an elevator as smooth as a conveyor belt surface: to do work, it is necessary to exert force on the object, and the person only has pressure on the elevator, and the direction of pressure is perpendicular to the elevator surface, that is, perpendicular to the direction of displacement, so no work is done.

If it is a staircase elevator: the pressure of people on the elevator is vertical downward, because the elevator has a partial displacement in the vertical upward direction, so people do negative work on the elevator; The downward elevator does the right work.

Without doing work, people are being done.

Yes. Gravity is straight downwards. The elevator is upward. So it is also counted as moving some distance in the direction of the force. In other words, you are doing work on yourself.

The person himself did not do the work, and the work required the person to exert force on the object and moved a distance along this force, and now neither of the two conditions is met, so he does not do it.

The question is not finished, there is. As long as there is a distance in the direction of the force, work is done.

If you just stand in the elevator, you don't have it.

If the elevator goes up, people will have to do their work.

No! But it depends on whether the person moves!

People do - work. The elevator does a good job of supporting people.

Man is workman.

Upstairs, that's the work that the earth does to people, not the work that people do. It's true that people don't do work, and the 3rd and 4th floors are right.

The transportation distance is different.

Usually, the elevator distance will be longer than the stairs.

Short speeds are different.

The speed of the elevator is faster than the normal version of the person going up the stairs.

Work is different.

The elevator is done by the motor, and the stairs are done by the people themselves.

Let's take a closer look at the relationship between forces.

When riding the elevator, the person is supported by a horizontal upward force, which will move the person to the target position, which is the most direct force used to do work. This force is usually given by the floor of the elevator.

This support force is the largest in the elevator starting phase, where the person will feel the acceleration, and the minimum in the stopping phase, which will feel a slight weightlessness. The intermediate process can be considered as a uniform motion.

When a person climbs a staircase, each step requires an upward and forward force, so the speed fluctuates and the magnitude of the force is uneven.

The support force does the work, f is up, and s is also up.

If you don't know, please ask.

There are the following reasons why the elevator in the hospital is operated by a special person, and it is also a very reasonable approach.

It can ensure the efficient operation of the elevator. If the hospital is very large, there are not only many elevators, but also a detailed division of labor, and the staff of the hospital sometimes can't figure it out, let alone patients and their families. With a dedicated elevator worker, the situation is much better, and the elevator can be used to the best extent.

In addition, emergency elevators and special elevators are even more so.

Able to help and maintain good order. Without elevator workers, especially hospital beds and wheelchairs, it would be almost impossible to enter the elevator during peak hours. In addition, pregnant women, the elderly, children, strollers, people wearing medical equipment, people with disabilities, etc., may not be able to squeeze into the elevator even if they are in line.

Therefore, hospitals need to protect vulnerable groups, and elevator workers are needed to maintain coordination.

Ability to minimize exposure and prevent infectious diseases. Everyone who enters the elevator has to press the elevator button once, and how many pathogens may be attached to the button. The elevator worker can solve this problem, press it alone, wear gloves, and disinfect it regularly.

It can effectively reduce the failure of the elevator. Every day, there are countless people pressing the elevator countless times, and the weight is scattered and so on, and the mispress, the wrong press, the heavy press, and the messy press in the big hospital are even more. With the elevator worker, the "damage" to the electric Xiangshi ladder can be greatly reduced.

Therefore, it is necessary for the hospital elevator to be operated by a special person, please be able to pay attention to civilization and social morality, respect labor, and consciously maintain public order.

It can ensure the efficient operation of the elevator. If the hospital is very large, there are not only a lot of elevators, but also a fine division of labor, and the staff of the hospital sometimes can't figure out what is the situation of patients and their families. With a dedicated elevator worker, the situation is much better, and the elevator can be maximized and optimally utilized.

In addition, emergency elevators and special elevators are even more so. Able to help and maintain good order. Without elevator workers, especially hospital beds and wheelchairs, it would be almost impossible to enter the elevator during rush hour.

When the elevator accelerates upward, the person is in a state of overweight, and the internal organs of the person are subject to the action of the upward resultant force, so the internal organs of the person will move downward relative to the human body, so A is correct, B is wrong and the branch is weak.

When the elevator accelerates downward, the person is in a state of weightlessness, and the internal organs of the person are subject to the action of the downward resultant force, so the internal organs of the human body will move up relative to the human body, so C is correct and D is wrong

Therefore, choose Tsaiyun AC

Take the elevator quietly upstairs, the elevator does work on people, and people's potential energy carries slag high.

When people go upstairs by stairs, they do their own work, consume physical energy, and their potential energy increases.

The elevator is load-bearing with a wire rope. Phosphate coated wire rope, preferentially using manganese or zinc-manganese phosphating, compared with the smooth wire rope production process, only the final wear-resistant phosphating treatment process is added, the wear resistance and corrosion resistance of the steel wire are greatly improved, and the steel wire is directly twisted after the use of phosphorus purification without cold drawing. The current fatigue test data show that the fatigue life of the phosphate-coated wire rope is about 3 times that of the smooth wire rope of the same structure (under comparable conditions in the laboratory).

According to the height of the hood w=g·h or w=f·s, the definition of work done is the force multiplied by the distance that the force moves in the direction of the object.

When taking the elevator, the person moves in a vertical direction, and the gravity is straight downward.

So gravity does the work.

When walking with a bucket, the pulling force is in the vertical direction, and the distance to move the green skin is in the horizontal direction.

So man did not work on the bucket.

1.You don't know about elevators, and elevators have a counterweight.

Suspended on both sides of the traction wheel, one side is the car, the other side is the counterweight (the weight is about 45% of the car weight + rated load).

2.Elevators go up or down, not necessarily consuming energy. Look at the load capacity.

When the elevator goes down, when the car side is heavy, the decrease of the gravitational potential energy of the car is greater than the increase of the gravitational potential energy of the counterweight, and the motor can be in the state of power generation. (If the energy feedback device is used, it can be fed back to the grid).

When the specific weight of the car side is light, the decrease of the gravitational potential energy of the car is less than the increase of the gravitational potential energy of the counterweight, and the electrical energy does work at this time.

When the car side is light, the synchronous host can be in the state of power generation when the car side is compared to the weight, the gravitational potential energy of the counterweight decreases, and the gravitational potential energy of the person increases, and the difference is electric energy.

If there is no energy feedback device, the elevator usually dissipates the energy through the braking resistor.

Haha, I've been working for many years, and I've forgotten all about physics, but I know about elevators.

This is a very understandable question, I ask you why people jump from the tenth floor and fall to their deaths, but they don't fall to their deaths when they take the elevator? The reason is that the elevator does work for people, and does not let people descend according to the free fall, which changes the force of people and reduces the descent speed. You can ask about it.

Thermal energy, or internal energy.

In the real world, almost all work processes are accompanied by the loss of heat energy, a simple example is frictional heat generation

Not only in the process of descending, there is also a loss of heat energy in the process of ascending, in addition, electrical energy is also converted into the gravitational potential energy of the elevator, etc., but not only the gravitational potential energy of people. The problem is that the difference between the input value and the RMS value of the work done is often the amount of heat energy lost, that is, the "energy that cannot be found".

However, there are often problems where the slider slides along a smooth plane, and there is no heat loss at this time, but this is only an ideal situation, and it does not actually exist.

When you stand on the ground and hold the box and do not move, it is not work, you feel exactly the same as the elevator at this time, but the elevator is doing work, why does it seem to be a contradiction, in fact, from the perspective of energy, if people do work on the ground, it consumes people's energy, and when people do work in the elevator, although they do not consume people's energy, they obviously consume the energy of the elevator's mechanical transmission device.

For the elevator to carry people up when the work is done, just like when a person scoops water with a spoon, the spoon does the work, but it does not consume the energy of the spoon, but consumes the energy of the person holding the spoon.

You need to select a ground frame of reference, not an elevator. For ground movement, the hand carrying the box does the work; If you don't move the ground, you won't do any work.

Whether or not to do work is a different concept from whether or not to do physical strength, and cannot be equated, and "exertion" is just the feeling of consuming energy to keep or change the body to a certain state.