Physics I think I m a master of Shinang, thank you!!

1.Liquefaction of water vapor.

Explanation: The white gas water that appears after the red-hot iron rod is put into cold water undergoes two changes in the state of matter, first the liquid water is heated and sublimated into water vapor (water vapor is invisible), and then the water vapor rises and liquefied into small water droplets when cold"White gas".

water vapor. Explanation: Because the water vapor of 100 is exothermic and condensed into 100 water, the heat of 100 is more radiant than that of 100, and the burn is more severe.

3."Pollen of white flowers"It is formed by the condensation of water vapor. "Smoke"It is formed by the condensation of the surrounding water vapor by a cold popsicle. "Khan"It is formed by the condensation of the surrounding water vapor on the outer wall of the cold teacup.

4.Water vapor in the bathroom is formed by condensation on the walls of cool iron pipes.

5.Fog is small droplets of water in a liquid state, and clouds include liquid water and solid ice.

Explanation: The cloud's is not very accurate because the water vapor condenses into small water droplets with dust at the core, and if the temperature at the height of condensation is below 0, the water droplets freeze into ice crystals. These water droplets or Xiaoice crystals are very small in size, and their cross-sectional diameter is usually only a few thousandths to hundredths of a centimeter, collectively known as cloud droplets.

These questions basically examine the understanding of the three forms of water.

There are three states of water: gaseous, liquid, and solid. Gaseous water is colorless and cannot be seen under normal conditions. What is generally seen is the small water droplets formed after the liquefaction of water vapor, which is the fog seen.

Because water is a crystal and has a fixed melting and boiling point, all the internal energy of water in different states is different at the same temperature. For example, 0 ice has a lower internal energy than water, and 100 liquid water has a lower internal energy than 100 gaseous water.

1.When the red-hot iron rod is immersed in cold water, white gas immediately appears, which is a phenomenon of "vaporization".

2.If you accidentally get burned by 100 water and 100 water vapor, which one is more serious? Please give us a review and explain why! It should be 100 water vapor burns. Because when the unit mass is the same, it has more heat.

3.In the summer, the salesperson took out the popsicle from the freezer and found that the hard popsicles were stuck with "white flower pollen"; As soon as you peel off the wrapper, there will be "smoke" on the popsicle, and if you put this popsicle in the teacup, after a while, the outer wall of the teacup will "sweat". "White flower pollen" is formed by water forming fine ice crystals.

"Smoke" is formed by the direct vaporization of ice into water vapor, and "sweat" is formed by the condensation of water vapor into water droplets.

4.The iron water pipes in the bathroom are often rusty, and if you look closely, you will find that there is always a thin layer of water on the surface of the water pipes, which will be there again after wiping them dry. Because the appearance of the water pipe is always damp, it is naturally easy to rust.

But where did this layer of wiped and existing water droplets come from?

Water droplets are formed by the condensation of water vapor in the middle of the air.

5.Fog is small water droplets in liquid form, and clouds include small water droplets in liquid form and solid dust.

1. When it is put in, it is vaporized, and the white gas is liquefied.

2. Water vapor, because the liquefaction of water vapor into water will release a large amount of heat to burn the body, and the water is still hot at 100 degrees after liquefaction.

3 Ninghua (in summer, the outside world provokes too much than popsicles); Liquefy; Liquefy;

4. Liquefaction. 5 liquid, solid (this kind of ice is too big to fall and not completely melt when it is hail), water, liquid, water.

1.Liquefy; 2.Water vapour; Because 100C water vapor has one more liquefaction temperature than water.

3.Water vapor condensation, water vapor condensation in the air liquefaction, liquefaction of water vapor in the air.

4.The water vapor in the air liquefies when it encounters a colder water pipe.

5.Liquid, solid snow and ice, liquid water droplets.

1.Liquefaction 2Water vapor, the liquefaction of water vapor field on the hand will release heat to the surroundings, so the temperature is greater than 100 degrees.

3.Sublimation; Liquefy; Liquefy;

4.Water vapor liquefies when it encounters colder water pipes.

5 Liquid, Solid, Ice, Liquid, Water.

Choose B, you have the wrong answer.

From the conservation of momentum, we can get: m1*v1=m2*v2 then v1:v2=m2:m1

Because f mill = *m*g a = f mill m = g (a is the acceleration, opposite to the direction of the initial velocity of m1 m2) so a1 = 1g a2 = 2g

t1=v1 a1 t2=v2 a2 t1 t2=(v1*a2) (v2*a1)=(m2*m2) (m1*m1) is not equal to 1 so the exercise time is not equal. B false.

s=v Beginning Now that we know the ratio of the initial velocity of m1 m2, the ratio of acceleration and the ratio of t1 t2, we can get the ratio of the distance.

After calculation, s1 is not equal to s2C false.

D, of course, is also wrong.

1. The answer should be d, the process of firing the cannonball is indisputable that the ship and the cannonball momentum are conserved. The key is to understand the relative velocity of the cannonball to the ship, and I think the velocity of the cannonball is the current velocity of the ship v2 plus the relative velocity v', so the answer is D.

First, the gravity force and the electric field force are synthesized into a new gravitational force, i.e., f=eq-mg=1 10-3nDirection: Vertical upwards. In this way, when viewed upside down, it is equivalent to an object sliding down an inclined plane. f=ufcosa=

The total external force is equal to fsina-f=1 10-3*, the acceleration is a=2m s 2, and the speed of gliding 2 meters is 2as under the root number = 8m s

The flash frequency is 10hz, so beautiful to take a picture once.

ob=16cm, when there is no interval between regrets, so the average speed of the ob segment is 16.

Point A is the midpoint of the OB segment, so the instantaneous velocity at point A is the average velocity of the OB segment.

In the same way, the instantaneous velocity at point B is the average velocity of the AC segment, and the instantaneous velocity formula (27-7) at point B can be obtained according to the above method.

The magnitude of acceleration is the difference between the two points of velocity ab divided by the time interval, so the magnitude of acceleration is (100-80).

The force analysis of the weight P shows that the tensile force t and gravity g of the string on the weight are a pair of balancing forces. So, t=g.

Also, the pulling force f and t of the weight on the string are a pair of action and reaction forces, so f=t=g.

From the sine theorem: f1 sin = g sin(90°+ =f2 sin(90°- =f2 cos.

1. Then f2 =gcos sin(90°+ =k sin(90°+ where k=gcos is the fixed value.

When decreasing from 90° to equal to , sin(90°+ value increases from sin to 1, f2=k sin(90°+ decreases from k sin to k.)

When decreasing from to 0, sin(90°+ the value decreases from 1 sin(90°+ f2=k sin(90°+ increases from k to g.)

2. Then, f1=gsin sin(90°+

When decreasing from 90° to equal to , sin decreases from 1 to equal to sin; sin(90°+ value increases from sin to 1, f1=gsin sin(90°+ decreases from g sin to gsin.)

When from to 0, sin from to 0; sin(90°+ the value decreases from 1sin(90°+ f1=gsin sin(90°+ decreases from gsin to 0.

From the above analysis, it is known that when the thin line BO gradually turns counterclockwise from the horizontal direction to the vertical direction, the tension of the thin line AO decreases from g sin to 0. The tension of the thin wire BO first decreases from GCOT to GCOS, and then increases to G.

Yes or no, please refer to it!

Well, you didn't give the picture, I don't know the specifics, right?

The force on AO decreases and the force on BO increases.

When the ob is in the process from horizontal to vertical: the original ob and the wall are perpendicular, and when it turns counterclockwise, the ob and the wall form a triangle. The right triangle has the longest hypotenuse, so ob >ob

oa, ob The resultant force remains the same, it is always equal to the gravitational force of p, ob is large, and OA becomes smaller, so I won't ask again.

The force on a0 decreases.

The force on b0 decreases first and then increases.

Solution: Q Suction = Q Discharge Q Suction = MC (T End - T Beginning) = 4 * 10 3 * 100 - 25) = * 10 6 Joules Q Discharge = MQ = M * 10 7) Therefore, M = ( 10 6) ( 10 7) = Cubic Meter Answer.

i=p/u=100a

The current is the same throughout the transmission circuit.

u=p/i=3kv

So the voltage of the resistor on the wire is 5-3=2kV

r=u i=20 ohms.

p out = i 0 5 = (500kv-450kv) 20i = 50a

u=500/50=10kv