Boring questions about physics, boring topics, physics

1.In the microscopic world, space (length), energy, etc., can only be measured in quantum states, where the smallest unit of length is called Planck's constant, and the order of magnitude is 10 -33 meters. The Planck minimum time does not mean that cosmic time is discrete, only that the minimum time observable by humans is discrete, while cosmic time is continuous and infinitely divisible, distinguishing from length, energy, etc.

2.Time and space do not theoretically have the mutuality you say, but energy does, and now antimatter can be made in the laboratory, for example, normal electrons with 1e are negatively charged, but antielectrons with 1e are positively charged, and the amount of charge is the same, but the polarity is opposite (the same is true for nuclei, and neutrons have opposite spins).

3.For example, if a table is made, it takes other energy (manpower and material resources) to turn disorder into order, but as time goes by, the table will only become more and more broken in the natural state, which is from order to disorder, but the energy consumed from disorder to order is always more than the energy consumed from order to disorder (efficiency problem), so the overall performance of the whole universe is that the entropy has been increasing (in the case of the chaotic universe, the last entropy of the universe is balanced everywhere).

As for the appearance of life or something, it is the same as white clouds, sometimes the clouds in the sky appear scale-like, which is contrary to order to disorder, scientists call this kind of phenomenon (including the origin of life) collectively called self-organizing phenomena, the mechanism of which is still unknown. But what is certain is that on a macroscopic scale, the entropy of the universe increases over time.

I think you have the potential to be a physicist of the future.

Philosophically there is no limit, but physically there is.

Questions 1 and 2 are recommended to watch "Science Fiction World".

3 Yin and Yang, gossip, go to see Zhou Yi. Combined with physics, the local entropy increases and the local entropy decreases to 0 as a whole, entropy has no relationship with time, entropy only represents the aggregation and dispersion of energy.

The velocity hunger difference of the ball falling to the lowest point is 0, so the work done by the electric field is equal to the work done by the gravity of the ball, so mgl=eql,eqd=uq,e=u d=200 ,q=,8*10 6c,because eq=mg,so the direction of the resultant force is 45° obliquely downward and vertically,so the speed is the largest when the reverse extension line coincides with the o point in this direction,so mgl 2=mv 2 2,v=

The OA distance is zero. x=at, so the distance difference is a fixed value of ......x total = 1 2gt total, x end = 9 25x, v end average = x end 1 second, v = gt end av = g (t total , solve the equation to get t total, bring in the first equation to get x total. (The end of x refers to the displacement of the last second....)

What you are talking about is that the sliding rheostat is connected in series with the consumer.

For example, a "3V bulb, connected to a 6V power supply, it will definitely be burned, because the voltage at both ends of the bulb is 6V, which is greater than 3V, and at the same time, the current through the bulb is also greater.

In order for the bulb to work properly, a sliding rheostat can be connected in series. In this case, the supply voltage is equal to the voltage of the lamp + the voltage of the sliding rheostat.

That is, the voltage of 6V is shared by the sliding rheostat, which is the voltage division;

Because the resistance in the circuit increases, of course, the current in the circuit also decreases, which is called current limiting.

Sliding rheostats are generally connected in series in a circuit. If it is connected in parallel, it cannot play the role of protecting the circuit.

The three-wire connection method of other sliding rheostats is not required for junior high school.

When the voltage at both ends of the electrical appliance is too high, it is necessary to choose the voltage divider connection. The so-called "voltage divider connection" is to connect the resistor in series to the circuit.

The total voltage of the series circuit is equal to the sum of the partial voltages.

When the current at both ends of the electrical appliance is too large, it is necessary to choose the shunt connection. How can I choose the partial pressure connection?

The voltage divider effect is only suitable if the voltage is too high.

When the power supply voltage is higher than the rated voltage of the electrical appliance, the voltage divider method can be used.

Voltage divider, that is, a lower voltage value is separated from the higher voltage to meet the use requirements.

Generally, the exam is to choose the score pressure, especially in the end, there is no time, just choose the score pressure, don't think about it, 95% is right.

Adopt me.

The analysis is as follows: Linear motion in which the magnitude of velocity does not change, and the direction of velocity changes This existence is such as: uniform circular motion.

Linear motion with the same magnitude of velocity and a change in the direction of motion does not exist.

Is there a difference between uniform linear motion and constant velocity linear motion? Yes. Uniform linear motion is a motion in which the magnitude and direction of velocity do not change, and constant velocity linear motion only limits the magnitude of velocity to remain unchanged in a certain period of time.

Hope that helps, hopefully.

1. The statement is contradictory, if it is a linear motion, there can only be two directions, before and after, and there must be acceleration when changing the direction of speed, and if it accelerates in a straight line, it will definitely change the rate (the magnitude of the speed), and it is impossible to reverse out of thin air without the same rate.

2 has velocity to move, so the direction of motion is the direction of velocity, and 1 is the same statement, both are wrong.

Constant velocity is constant velocity, and velocity refers to velocity rather than velocity.

1. The first one exists, the second one does not exist, because the first one can move in a straight line, but one in the positive direction and the other in the negative direction. 2. Uniform linear motion should be the same as the size and direction of the speed, and the constant velocity is just the same size. (The above is purely a personal opinion, please understand that there is something wrong).