Grade 9 Physics Midterm Review Practice Sample Questions

Chubby was mistaken.

Known: M wine = wine =, soy sauce =

Seeking: M soy sauce.

Solution: v=m v to v=m wine wine=

v soy sauce = v sake =

Obtained by =m v m soy sauce = v soy sauce soy sauce =

Answer: The quality of soy sauce is , and it will not fill the bottle, and Chubby's judgment is wrong.

If you don't understand something, ask it.

Known: M Wine = M Sauce = Wine = kg M3, Soy Sauce = kg M3: V Wine V Sauce.

Solution: v wine = m wine kg m3

v sauce = m sauce soy sauce kg m3

V wine V sauce.

The soy sauce is not filled.

Answer: Chubby is mistaken.

The volume of the wine = the volume of the bottle = v1=

Volume of soy sauce v2=

v2< v1, so it's Chubby who made a mistake.

1 cm has = 10 8, 1 square centimeter has 10 16, population 6x10 9, how many times?

Divide the length of the side by the diameter of the molecule (remember to convert the unit) to get the number of molecules on each edge, and the square of the number of molecules is equal to the total number of molecules. The total number of molecules divided by 6 billion is a multiple.

(1) When fully loaded, because the force is balanced on the water surface, the gravity is equal to the buoyancy, g = f float = mg = 5000 * 1000 kg * 10n kg = 5 * 10e7 n

2) F float = p seawater * g * v row = g.

Combining the results in (1) and the density of seawater, it is obtained that v row = m3

3) When the density of sea water increases, since the gravity and buoyancy of the destroyer remain unchanged, according to the analysis of the formula in (2), it can be known that the V row becomes smaller, that is, the destroyer will float a little...

Because friction is not counted, the extra work is equal.

Mechanical efficiency = w useful work w total work , the first time is different from the second useful work, the first useful work is less than the second useful work, so the mechanical efficiency 1 is less than the mechanical efficiency 2

The extra work is the work done on the pulley, the weight of the two pulleys is the same, and the height of the lift is also the same, so according to w=fs, the extra work is equal.

The first time there is less water, so less work is done on water, i.e., less useful work, according to = useful work (useful work + extra work), so 1 2

Buoyancy f=mg

P wood = f (buoyancy) a 3

m (wood) = f (buoyancy).

v (immersion) = m p (water).

v (exposed) = a3-v (immersion).

Pressure difference = f (buoyancy) a 2 = lower surface pressure.

m wood = mg wood = m g (g is the gravitational constant).

f float = g wood = m g

v-wood = a3 (3 is to the 3rd power).

density) wood = m v = m a 3 (3 is the third power).

The gravitational force of the wooden block g = gm, the mass of the wooden block m = the mass of water overflowing in the cup m, the buoyancy of the wooden block f floats = g object, the density of the wooden block p, the pressure of the water on the low surface of the wooden block is p = gm divided by a squared! You can see it! I've probably thought of these 5!

i=2000w 220v= r=u2 p=220*220 2000=ohm.

w suction = w electricity = 2000*

Efficiency = thickened liner to strengthen thermal insulation performance.

Xiaohua said it more accurately. Xiao Ming said: "In a parallel circuit, the current of the trunk circuit is greater than the current of any one branch.

It just shows that the trunk current is larger than the branch current. And Xiaohua said: "In the parallel circuit, the main current circuit is equal to the sum of the currents of each branch.

This is a more appropriate statement that better illustrates the exact relationship between the trunk and branch currents in parallel circuits.

Xiao Ming said it more accurately.

The current in the trunk circuit is not equal to the sum of the currents in the branches.

Because there is also a loss of current used to heat the dead wire and reduce the current, so it should also be added to the loss of the current that heats the wire is more accurate, well, it should be like this, hehe.

"Title Poshan Temple Hou Zen Courtyard" is a poem by the Tang Dynasty poet Chang Jian. Poshan Temple, improvised Fuji Temple, is located on Yu Mountain in the northwest of Changshu City, Jiangsu Province. The poem expresses the perception of visiting the temple in the early morning, the pen tone is simple, the description is provincial, the image is profound, the artistic conception is harmonious, and the art is quite complete, which is a unique famous piece in the landscape poetry of the Tang Dynasty.

Title Poshan Temple after the Zen Temple.

Tang) Chang Jian. Early in the morning into the ancient temple, the first sun shines on the high forest.

The winding path leads to the secluded place, and the flowers and trees in the meditation room are deep.

The mountain light is pleasing to the birds, and the pond shadow is empty.

Wan Lai is silent, but Yu Zhong chimes.

Excerpt from "All Tang Poems".