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The physical meaning of G = 9.8n/kg is______ ．
G stands for gravity, the unit is n, m stands for mass, the unit is kg. The relationship between gravity and mass: g = GM, the unit is n / kg, so the physical meaning of G is: the gravity of an object with a mass of 1kg is 9.8N. So the answer is: the gravity of an object with a mass of 1kg is 9.8N
In physics, g = mg, where g = 9.8n/kg. What does g mean?
Is g the speed at which an object falls?
If so, will it change? For example, if an object falls from different heights, it bears different forces and its speed is also different. If an object falls from the 10th floor or the 1st floor, the time of falling from the 10th floor is different. What role does constant G play here?
Here's g, as you'll learn in high school, it's acceleration of free fall, also known as acceleration of gravity, it's not velocity
On the surface of the earth, the value of G varies slightly, but it is very close to the value of 9.8 (International System of units)
In junior high school, because of limited knowledge, we usually say g is a constant
For suspension and floating, is there a formula F floating = g discharge = g matter
Yes
The first equation is the expression of buoyancy obtained by Archimedes, which holds even for a sunk object
The second equation is derived from Newton's first law of motion. The object is stationary, so the external force equals zero, so buoyancy equals gravity
The relationship between F and G in floating, floating and sinking
For example:
Floating: F floating G
Suspension: F-G
Sinking: F floating G
(fill in "" on the horizontal line)
It's better to have a detailed explanation, but not too messy,
Floating: F floating = g
According to Archimedes principle, the volume of liquid is less than the volume of object, so the density of object is less than the density of liquid
Levitation: F = g
According to Archimedes principle, the volume of liquid is the original volume of the object, so the density of the object is equal to the density of the liquid
Sinking: F floating
F floating = g liquid discharge = ρ liquid GV liquid discharge floating V is less than suspended F, then why floating f = suspended f
Explain the details, otherwise I will not set 100 points``````
First of all, you need to make clear two concepts: floating means that the object is completely submerged, and suspension means that the object is suspended above the liquid
Floating f = g discharge = ρ discharge = weight of object
In suspension, f floats = g discharges = ρ discharges gvdischarges = weight of the object
But in these two cases, the mass of the object is not the same, so V discharge is not equal
Take a simple example: table tennis and small wooden ball can float on the water surface, and when they float, f = the weight of the object, but because the two weights are not the same, so the V drainage of the two is not equal. The analysis method for the same object is also similar. We need to analyze according to the force of the object, I don't know if I'm detailed enough
When an object floats or floats, does it have f = g object?
Not necessarily
There are conditions
1. When the object is floating or floating, if there is external force acting on the object (for example, when floating, you can use your hand to pull up the object a little)
In this case, f is not equal to g
2. When an object floats or floats, there is no external force acting on it. At this time, f floats = g object
Why can't we use f floating = m row g except floating and floating?
Does immersion include suspension? If so, why can't f float = m row G?
What you said is wrong. It can be used, it must be used!
Because only levitation and floatation are in equilibrium
Both floating and floating can use f floating = m row g. immersion includes suspension
Just pay attention to how to calculate row M
M row = P liquid V row, V row is the volume of the object immersed in the liquid
In the suspended state, V row = V object, which can be replaced by the volume of the object itself
Is m in F = g = mg the weight of the object or the mass of the discharged water?
Both are
① The molar mass of Mg is 0______ The mass of 1 mol mg is 1.5 g / mol______ g. 5 molmg______ g
The molar mass of Mg is 24g / mol, the mass of 1 mol mg is 24g, and the mass of 0.5 mol mg is 12g
Where g = mg, G is gravity, M is mass, what is g
Where g = mg, G is gravity in N, M is mass in kg, and G is acceleration of gravity in N / kg
be careful:
1. For example, the acceleration of gravity on the moon is only 1 / 6 of that of the earth;
2. In physical calculation, g = 9.8n/kg or g = 10N / kg is usually used
RELATED INFORMATIONS
- 1. Under what conditions is f floating = ρ liquid GV discharged, under what conditions is f floating = g discharged, f floating = m discharged, G discharged
- 2. Some questions about buoyancy in junior high school physics 1. A 100 cubic centimeter object is hung under the spring dynamometer. When the object is immersed in water, the indication of the spring dynamometer is 1.7n__ N 2. Put a solid aluminum block with a mass of 27g into a beaker filled with water. When the aluminum block is still in water, the mass of water discharged from the beaker is__ g. Put the aluminum block into a beaker filled with alcohol, and the mass of the discharged alcohol is__ g
- 3. When measuring the density of a small solid object, a physics interest group adopted the following experimental operations: first, the mass mo of the object was measured with a balance; then, a certain amount of water was put into a small beaker, and the total mass M1 of the beaker and water was measured with a balance; then, after the object was tied up with a thin line, the mass M1 of the beaker and water was measured, The object is immersed in the water of the beaker (the water does not overflow and the object does not touch the beaker) by holding a thin line in hand. At this time, the measured value of the balance is m2, as shown in Figure 6 A. The buoyancy of an object in water is MOG B. The buoyancy of an object in water is (m2-ml) g C. The density of the object is Mo / m2-m1 * P water D. The density of the object is Mo / m2-m0 * P water 、 I don't understand at all. I'm going to take the senior high school entrance examination right away. It's really disturbing that I don't understand
- 4. All the formulas for buoyancy and pressure
- 5. A course of junior high school physics [pressure and buoyancy], This is the physical simulation of Haidian District in Beijing in 2009 As shown in the figure (a cylindrical container contains a plastic box, in which an iron block floats on the water surface), the cylindrical container with bottom area S1 contains liquid with unknown density. Put a cube metal block with density ρ into the rectangular plastic box with bottom area S2 (the thickness of the plastic box can be ignored), The plastic box floats on the liquid surface (the liquid will not overflow the container), and its immersion depth is H1. If the metal block is taken out of the plastic box, it is tied under the plastic box with thin wire, and put into the liquid, the metal block does not contact the container, and the immersion depth of the plastic box is H2. Cut the thin wire, the metal block will sink to the bottom of the container, and the plastic box floats on the liquid surface, The depth of immersion is H3. If the plastic box is always upright without inclination, the pressure of the liquid on the bottom of the cylindrical container is reduced before and after the thin line is cut? Two supplementary points: 1. The density of the liquid in the container is unknown, and the expression should not contain ρ liquid. 2. The question is how much pressure has been reduced. Not why.
- 6. Who listed the related formulas of physical pressure and buoyancy one by one, including Rou = m / V, which is not published in textbooks? Don't take too many words to explain in front of me. Just tell me what the physical quantity is. I want to copy and paste it
- 7. In a bathing beach, the bottom of the water is full of stones. In the process of swimming from deep water to shallow water, the following experience and analysis are reasonable () A. Feet are getting more and more painful because water has less and less support for people. B. feet are getting more and more painful because people are receiving more and more gravity. C. feet don't hurt because people are getting lighter and lighter. D. feet don't hurt because water has more and more support for people
- 8. buoyancy A and B are liquid and solid respectively. The density of liquid a is 1g / cm3, and that of solid B is 0.5g/cm3. When a solid solid (composed of substance B) with a volume of 10-3m3 is put into a container containing enough liquid of substance A, how much buoyancy does the solid solid receive when it is still? How much volume does the liquid displace?
- 9. All formulas of buoyancy Buoyancy knowledge explains all the variant formulas of buoyancy
- 10. The meaning and calculation formula of 1 ＼ G 2. On buoyancy formula
- 11. What's the meaning of ml / dl? How to read it? What's the difference between ml / dl and Mg / dl
- 12. Conversion of kg and Mg 72kg = 10 to the seventh power mg
- 13. What is Archimedes' formula of buoyancy principle An object is subjected to upward buoyancy, which is equal to the gravity of the liquid displaced by the object!
- 14. Why is the buoyancy equal to gravity when an object floats or floats? The volume of water overflowing during floating is different from that during suspension. Why is the buoyancy the same?
- 15. Why not use Archimedes principle to calculate the buoyancy of floating objects? The teacher said that when floating, f floating = g object can discharge liquid according to Archimedes principle. That is to say, the buoyancy has something to do with the volume of the immersed liquid. Isn't there part of the floating that is not completely submerged? How can we say that f floating = gravity? These two problems can be calculated in both aspects What kind of application is it? When and how to use it? What's the difference
- 16. The pressure on the lower surface of the board is equal to the buoyancy f = f floating = 6N?
- 17. Under what circumstances f-f = ma. How to calculate the external force of f-f = ma
- 18. Why is f equal to ma
- 19. What does f-mg = ma mean?
- 20. What is a in F = ma? What does a mean when the rocket accelerates up?