Special physics, physics problems! Very urgent!

It's hard to be vertical, but it's easy to tilt a little bit, and if you rotate the house at high speed, the support force on the wall will be oblique upward, and then part of the vertical force will balance the gravity, and the other part will be perceived as the "attraction" of the wall to the person, and the person can walk on the wall.

When a person is perpendicular to the wall, the n pole of the electromagnet on the body is opposite to the n pole of the electromagnet on the ground, and the gravity is offset by the repulsion between the electromagnets.

Do you want to learn to be a thief?

As a possible solution, you'd better be in a crawling position while on a wall.

A negative pressure generating device that allows atmospheric pressure to press you against the wall, creating the right amount of pressure to match the coefficient of friction of the material you are wearing. mg=ups

m your mass, u coefficient of friction, p negative pressure and atmospheric pressure difference. Half of your body surface area.

This is your approximate formula.

Disadvantages: The pump for negative pressure pumping is loud and has no safety device to avoid falling.

In an environment where there is no gravity.

A rotating huge cylinder with an empty interior.

We clinged back to the cylindrical wall.

Note that it's not the underside, it's the side.

And you can walk up and down.

The principle is that the centripetal force becomes the gravitational force.

But the direction is not vertical.

It's horizontal.

That's it.

My expression may not be clear.

Specifically, you can+

Add a force to your back to balance your gravity, and the force defense line must pass through the center, so it is recommended that you get a rocket.

Blowing people up with an electric fan.

Borrow buoyancy in the water (of course the wall is in the water).

In space. Put a gold coin on top of you, and you float yourself with your mind.

The legendary out-of-body can also be.

Or hollow out the earth or find someone to make another touch of the earth on your head.

It's simple, as long as the wall is not perpendicular to the ground, but at a certain angle.

Your question is interesting, this friend. First of all, I'm not here to get points. I'm specialized in physics-mechanics. I've never heard of this happening on Earth. Because at this time, the force analysis of people. The combined force of human force will not be 0.

So this may be beyond the scope of physics research.

I appreciate your thinking.

Push the wall on, and you stand on it and walk. Hehe, you didn't say the wall should be straight.

Concentrate the chakra on your feet.

There are special devices on the shoes, please refer to the various science fiction movies.

Method 1 is better.

This is because the speed at which an object dissipates heat is directly proportional to the temperature difference between the object and the environment. In the first way, the temperature difference between the coffee and the environment is large, and the heat dissipation is fast.

In the second way, cold coffee is added first, and the temperature difference between the coffee and the environment is smaller than the first one, and the heat dissipation speed is also less than that of the first one.

The cooling effect of method 1 is good. Reason: The first type has a small mass, and the temperature drops much after 5 minutes of cooling; The second one has a little milk added to it, which is of great quality and has less temperature drop.

A right. When the coil of the DC generator rotates, an alternating current is generated, and after the two brushes are switched (commutator), direct current (pulse direct current) is output outward.

If you choose A, you can see that the power generation part is exactly the same as the alternator, so it generates alternating current, and converts the alternating current to direct current through an external device.

1) The faster the gas velocity, the lower the pressure.

2) F=(P-P-Outside)S=(100000Pa-90000Pa) 60m2=600000N

1) Why does the air pressure drop dramatically outside the house?

The cyclone creates a centrifugal force, which causes the pressure at the center of the hurricane to drop.

2) Find the force on the roof due to the difference between internal and external pressure.

The indoor air pressure is 1 atmosphere 100,000 Pa, and the outdoor air pressure is 90,000 Pa.

f=p*a=（100000-90000）*60=600000n

If A is water, B is salt water and the mass is equal. When the same egg is placed in two cups of A and B:

a =b =

a Floating or levitating buoyancy is equal to gravity.

b p b b p a s equal, according to f = ps , then

C The liquid volume of the egg in B is small, so the density of the liquid in B is greater than that of A, and H is the same.

One by one.

1. For example, if the person carries the bucket for example, if it is lifted and completely immovable, the ideal situation is that the bucket will not consume the energy of the human body after it is lifted, but the reality is not the case, the muscle fibers of the human body provide force to overcome the gravity of the bucket in the case of tension, if the force provided by the muscle fiber tension always maintains this fixed value, it is equivalent to a stone statue at this time, and it will not consume energy. But the fact is that we feel sore after maintaining it for a period of time, this soreness ** produces lactic acid in anaerobic respiration of muscles, why is there lactic acid produced, this is because human muscles cannot provide constant force of the bucket like a stone statue, this force is a variable force, large and small, that is to say, the height of the bucket is constantly changing in the actual situation, and the muscles will be tense and relaxed in this process, and the muscles will consume energy in this process.

2. There are two situations for the motor to lift the elevator:

Clause. First, the elevator is not overweight. In this case, the motor does not convert energy to the elevator, the reason why the elevator does not move, is because the motor does not rotate, the elevator does not rotate because the motor is generally equipped with electromagnetic brakes, this device can lock the motor shaft after power-on, and the motor shaft can rotate freely after power-off, then it can be known that the energy consumption of the motor at this time is on the electromagnetic brake, it locks the motor shaft, and the elevator will not move;

Clause. Second, the elevator is overweight. In this case, the pulling force provided by the motor is less than the gravity of the elevator, the axial force of the motor is too small to rotate, the electromagnetic brake has no effect at this time, the current passes through the winding of the motor, and the energy obtained by the motor is all converted into the heat energy of the internal circuit, and the heat generation is much greater than when it rotates, and the energy of the motor will not be transferred to the elevator but converted into a large amount of heat, which is why the motor is easy to burn out when it is overloaded.

Haha, I'll give you another question Mention that the bucket consumes human energy (chemical energy can also be said to be biological energy) to convert into the potential energy of the bucket, so doesn't the process of putting down the bucket consume human energy Turn to ** Even the potential energy of the bucket is less Hehe.

Teach you the analytical methods for analyzing energy conversion problems, 1 from the result analysis process 2 analysis process to find the result. The problem you said and the question I gave you are easy to understand by analyzing it in the first way. That is, first analyze what forms of energy may be involved in the transformation, and then analyze how it is transformed.

The process of lifting the bucket energy may be converted between gravitational potential energy, the chemical energy of the human body and the thermal energy, and the problem is solved in half. In the analysis process... In the process of lowering the bucket, the chemical energy of the human body, the gravitational potential energy of the bucket, and the potential energy of the bucket are converted into heat energy through the stretching and twisting of the muscles.

The electric motor stops in the air with the gondola, and the electrical energy consumed by the electric motor is converted into heat. For there is no other form of energy involved in the transformation ... It's as simple as that, and then you're in the process of analyzing the results by this.

If you don't supply power to the elevator, will the elevator fall? When the cable is not powered by the motor, it is fixed and has a pulling force; It doesn't fall even if the power goes out. Otherwise, as soon as the power goes out, the elevator will fall, and the elevator damage rate is extremely high, because power outages are commonplace. So the motor has no power consumption.

And when a person lifts a bucket, the force exerted by the human arm does not do work. But to generate this force, multiple organs in the body need to consume energy. So the energy is not spent on the bucket, but on the pulling force.

It is the power consumption of the work of the internal organs of the human body, and the energy consumed by chemical reactions such as heat dissipation, muscle contraction, and lactic acid production.

The object has gravity, the elevator is pulled upwards by the wire rope, the provider of the pulling force comes from the electrical energy, if the current disappears, the steel wire will no longer provide the pulling force, the elevator falls, so the current remains constant to provide electrical energy to fight against the gravitational potential energy generated by gravity.

Consumed bioenergy is converted into sweat or other metabolites.

Haha, I've thought about this too, and the power will be cut off right away, and I'll give it to you tomorrow.

。。The landlord's question is interesting, I'll copy it first, think about it later.

Ampere's rule, the direction of the magnetic field is determined by the direction of the current known;

The left-handed rule, knowing the direction of the current, the direction of the magnetic field, judging the direction of the ampere force and the Lorentz force;

The right-hand rule. The direction of the magnetic field is known, the direction of movement in which the conductor cuts the magnetic inductance line. Determine the direction of the induced current.

Amperectine is to judge the direction of the magnetic field of the energized solenoid, the left-hand stator is to judge the force of the energized wire or moving charge in the magnetic field, and the right-hand stator is to judge the potential of the moving conductor in the magnetic field

Judgment force with the left hand, (ampere force, Lorentz force,) other with the right hand.

Let the muzzle velocity = 0

Then m will be stationary in the horizontal plane and will never reach b, but t1 > t2 will be reached through the smooth arc groove

The general method will not, what do you mean by special?

If the T1 large object moves along the arc groove, it is an acceleration process from the top of one end of the groove to the lowest end of the groove, and then from the lowest end of the groove to the top of another section of the groove, it is a deceleration process. That is to say, the minimum velocity of this motion is the muzzle velocity, and obviously the average velocity is greater than the muzzle velocity.

And along a smooth horizontal plane, it is always muzzle velocity.

The distance is the same, and naturally T1 is larger.