Where is the energy consumed in a 4WD Please explain in detail 20

In general, it is the conversion of electrical energy into internal mechanical energy. There are many kinds of internal energy, including motor and battery heat release Among them, the motor heat release is not only because of resistance, but also eddy currents. Placed in a conductor in a time-varying magnetic field, eddy currents are generated, such as the core of a transformer, in which there is a time-varying magnetic flux, which generates an induced electromotive force on the secondary side and also in the core, resulting in eddy currents.

These eddy currents heat up the core and consume electricity. In order to reduce eddy current losses, the core is often stacked with many thin sheets of ferromagnetic conductors (e.g. silicon steel sheets), which are separated into a trapezoidal shape and coated with a thin layer of insulating varnish or insulating oxide. As the magnetic field passes through the narrow cross-section of the sheet, the eddy currents are confined to a few narrow loops in the sheets, where the net electromotive force is smaller, the length of the loops is larger, and the eddy current losses can be significantly reduced due to the high resistivity of the sheet material.

Therefore, laminated cores are widely used in AC motors and electrical appliances.

Regarding friction, the negative work is mainly the friction between the tire and the ground, and the friction between the gears.

If it is not a toy car, the energy consumption of four-wheel drive is such as the rolling friction loss between the tire and the ground, the rolling friction resistance loss between the tire shaft and the bearing, the resistance loss of the front and rear wheel transmission distribution, the pressure friction resistance loss between the transmission shaft and the pin or key, the friction resistance loss between the gear pulley transmission, the rolling friction resistance loss between the engine crankshaft and the bearing, the friction resistance loss between the engine piston and the cylinder wall, the hydraulic loss and the mechanical friction resistance loss in the hydraulic transmission device, Friction resistance loss in headwind, uphill resistance loss of automobiles, loss of acceleration resistance, loss of turning friction resistance, etc.

I don't know if you're talking about a toy car, in addition to being used as kinetic energy, most of it should be consumed at the bearing, toy cars seem to be sliding friction bearings, so it is very energy-consuming, and the gear transmission, tires and road surface are rolling friction, it should be less.

The internal electrical energy is converted into mechanical energy loss, and part of it is converted into thermal energy.

Total energy expenditure refers to the amount of energy required to maintain basal metabolism; Energy expended in activities such as daily living, study, physical exercise, and labor; The amount of energy expended by the special motive action of food.

muscles and energy that sustains the basic activities of life.

In 2007, world primary energy consumption totaled 11.1 billion tonnes of oil equivalent.

The Earth produces 220 billion tons of biomass through photosynthesis every year, which contains 10 times the energy consumed by the world, but is currently used at less than 3%.

The total amount of energy consumed by humans on Earth each year accounts for 10 percent of the energy that the Earth receives and stores from the sun each year

It refers to the energy expenditure of the whole day, including resting energy expenditure, special kinetic effect of food, and basal energy expenditure.

A false sliding friction hinders the relative motion of an object, not necessarily negative work, may not do work, for example, if an object slides on the ground, the earth is subjected to sliding friction, but because the earth is relatively stationary, the earth does not do work.

For example, the object on the conveyor belt, the friction is large enough, and there is no relative motion with the conveyor belt, and it moves forward together, the friction force brought to the object is forward, the object moves forward, and the static friction force does positive work.

c False Not necessarily Possibly positive work may or may not be done negative work Reason such as option A.

D False A pair of interaction forces, if the action force does positive work, then the reaction force does not necessarily do negative work For example, put two magnets at a distance and then let go.

They all move towards the middle, and the attraction between them is a pair of action and reaction forces.

In this way, both of them are doing the right thing.

All four options are wrong.

A, wrong, sliding friction does not necessarily do negative work, w = fs, as long as the direction of the force and the direction of displacement are consistent, that is, positive work, for example, the object on the conveyor belt, may not be large enough, will move relative to the conveyor belt, the sliding friction of the object forward, the object also moves forward, so the friction force does positive work, the friction force of the object is backward, the belt is forward, and the friction force does negative work, so A says that it is certain, and the statement is wrong.

For example, the object on the conveyor belt, the friction is large enough, and there is no relative motion with the conveyor belt, and it moves forward together, the friction force brought to the object is forward, the object moves forward, and the static friction force does positive work.

c. The same reason is the same, wrong.

Option D is the correct answer.

A, false, let's take an example, there is a high-speed moving belt, at this time we put an object lightly on the belt, then the object will go in the direction of the belt, because the belt speed is very fast, assuming that when you just put it on, the belt and the object slide relatively, so the force that pushes the block to move is sliding friction, and along the direction of the block movement, do positive work.

b。Wrong, still use the above example, but to change it, a stationary belt is placed on a stationary block, and now the belt is slowly accelerating, so that the block follows the uniform acceleration movement, because it is slowly accelerating, so the block does not slide relatively, at this time, it is static friction, and the direction is consistent with the direction of movement of the block, and it does positive work.

c is the same as b error.

d First of all, it is clear that the action and reaction forces must act on different objects, that is, if I push a block with my hand, I am a force on the block, and the block is a reaction force on me. And the force does positive work, that is, I do positive work on the block, that is to say, my energy is transferred to the block, then my energy is reduced, that is to say, the reaction force does negative work, so that my energy is reduced.

The work done by choosing d is the product of force and displacement.

It depends on whether the force and displacement direction are the same.

It's all wrong, ABC won't talk about it. Upstairs, the answer to d is magnetism, which is rather mysterious and should not be taken into account. Explained by friction.

The two pieces are stacked on top of each other, keep the upper piece still, pull the lower piece, and the friction between the two pieces does not do work, because there is no displacement in the direction of the force, and both are converted into internal energy.

The positive and negative aspects of the work done by d are relative, so it is strictly forbidden to say d.

ABC can find physical objects to overturn.

I only know the use of a few.,If you want to make it clear, you'll have to find a great god to answer.,I suggest you go to the four-wheel drive bar and post a question.

Adopt my question, QQ private message to you This is not clear.

The 4L is a low-speed four-wheel drive.

4H is a high-speed four-wheel drive.

2H is a high-speed two-wheel drive.

Four-wheel drive, just drifting around-

1.Accelerate before entering the corner, align the apex of the curve when entering the corner, cut the steering wheel firmly and press the brake to downshift2The car glides into corners in a slightly forward-wheel drive manner.

3.When cornering the apex, press the throttle to increase the speed and safely go straight out of the corner 4This is professional-grade.

The difficulty factor is very high.

In the process of high-speed operation, the sudden braking will make the car have a tendency to continue to move forward, which will make the rear wheels slightly lifted (that is, the tail cocked), and the rear wheels will suddenly lose their grip, and the back will be the same as the landlord said!