Who has 8th grade physics 1, who has 8th grade physics

That version of Ah, what is it taught?

Solution: v steel = v aluminum = v

m steel - m aluminum = 104

Steel v Steel - Aluminum v Aluminum = 104

v ( steel - aluminum) = 104

v(v=20cm^3

Because =m v

So m Aluminum = Aluminum v Aluminum =

A: Aluminum 54g is required

The change of m = ( steel - aluminum) v = 104g, from which the volume v can be calculated, then m aluminium = v * aluminium = 39g

1, the principle of d thermometer is thermal expansion and cold contraction, the same temperature volume expansion is the same, the coarser height will be lower;

But the thicker tick marks are also more encrypted, and both measure the same temperature of 2,acd

Any measure that raises the mercury column of the thermometer can improve accuracy.

3,a100/(95-15)*(29-15)=

Use your brain more and ask such a simple question.

The thermometer has a characteristic, the finer the inner diameter, the higher the sensitivity, so the D thermometer has a characteristic, the finer the inner diameter, the larger the volume of the glass bubble, the higher the sensitivity, and the liquid that is easy to expand should be used.

The unit of the thermometer is Celsius, and the measurable range of the thermometer (0 -100) is known, the thermometer may be a cold and summer meter or a laboratory thermometer, so the graduation value is 1 in one grid, so the real temperature is 100 (95-15) * (29-15) =, so choose A

The first one, which should be an echolocation system, is simply a sonar.

Second, the depth of the sea = (speed of sound * time) 2 = (1500 * 6) 2 = 4500km, because the sound wave is the distance between two seabed depths, so it should be divided by two.

Thirdly, width = (speed of sound * time 1) 2 + (speed of sound * time 2) 2 = (330*, the reason for dividing by two is the same as the second question.

I hope it helps you, if you have any questions, please feel free to ask!

Test point 5: The understanding and application of the image is widely used in the process of solving problems because the image can intuitively represent the relationship between the physical process and the physical quantity. In kinematics, the x-t image and the v are often used

b b Because the optical path is reversible.

d The focal length is 10cm, which is smaller between 1F and 2F.

1. The vertical height of the liquid becomes smaller after inclination, and according to P=HPG, it can be seen that when H becomes smaller, P becomes smaller. f=ps, when p becomes smaller, f also becomes smaller. So fill in "get smaller".

When the object is hung under the spring scale, the spring scale shows f=g, when half of the volume of the object is immersed in water, the index f=g-f floats, and the indicator decreases by 1n, indicating that the buoyancy force on the object f floats = 1n; If the object is completely immersed in water, the buoyancy force f floats = 2n, then the spring scale shows f = 3n, according to f = g-f float, there is 3 = g-2, g = 5n

So fill in "1n", "5n".

The pressure does not change (because the atmospheric pressure value does not change, the height of the liquid does not change), the pressure increases.

Buoyancy 1 Newton, weight 5 New.

The amount of buoyancy on the object is related to the volume of the liquid and the density of the liquid, and the larger the volume of the liquid in the same liquid, the greater the buoyancy force; The pressure of the object is related to the distance of the object from the liquid surface and the density of the liquid, and the greater the distance from the liquid surface in the same liquid, the greater the pressure A False The volume of water discharged from the wooden block is smaller than the volume of the water discharged by the iron block b Yes The volume of the water discharged by the iron block and the copper block is the same c False The buoyancy does not change d False The density of alcohol is smaller than that of water The buoyancy of the copper block is small.