Know how force counts as energy

1.

1. Gravity g = mg

(vertically downward, g = 9.8m/s2 ≈ 10m / S2, the action point is at the center of gravity, applicable to the earth surface)

2. Hooke's law f = KX

{along the recovery deformation direction, K: stiffness coefficient (n / M), X: deformation variable (m)}

3. Sliding friction force F = μ FN

{opposite to the relative motion direction of the object, μ： Friction coefficient, FN: positive pressure (n)}

{rrrrrrr}

extended data:

different classification of force

1. According to the nature of force, it can be divided into gravity, universal gravitation, elastic force, friction force, molecular force, electromagnetic force, nuclear force, etc Note that gravity is not equal to gravity under all conditions Gravity does not point to the center of the earth under all conditions. Gravity is a component of the earth's gravitational force on an object, and the other component is a centripetal force. Only on the equator does gravity point to the center of the earth.)

According to the effect of force, it can be divided into tension, tension, pressure, supporting force, power, resistance, centripetal force, restoring force, etc

According to the research object, it can be divided into external force and internal force

According to the action mode of force, it can be divided into non-contact force (such as gravitation, electromagnetic force, etc.) and contact force (such as elastic force, friction force, etc.)

There are four basic interactions (forces): gravitational interaction, electromagnetic interaction, strong interaction and weak interaction

nature of force:

materiality: force is the effect of an object (matter, mass) on an object (matter, mass). When an object is subjected to a force, another object must exert this effect on it. Force cannot exist independently without an object

interactivity (interaction): the interaction between any two objects is always mutual, and the object exerting the force must also be the object under the force. As long as one body exerts a force on another, the stressed body in turn will surely add a force to the exerted body Generating conditions: the force is equal in size (the resultant force is zero, in a state of non directional static motion) or not equal, in the opposite direction, acting on two different objects, and acting on the same straight line. It can be summarized as: foreign body, equivalent, reverse, collinear. A pair of interaction forces must proce and disappear at the same time.)

Vectoriality: force is a vector, which has both magnitude and direction

simultaneity: the force proced and disappeared at the same time

independence: the effect of one force does not affect the effect of another

includes three elements: the size, direction and action point of the force. The accurate expression of the three elements of force by a directed line segment is called the diagram of force. The size is represented by the length of a scaled line segment, the direction is represented by an arrow, the point of action is represented by an arrow or the tail of an arrow, and the straight line along which the direction of a force follows is called the line of action of a force. The diagram of the force is used for the calculation of the force. When the judgment power is large, we must pay attention to the scale of the line segment, because even if one line segment is longer than another line segment, but the scale of the long line segment is also longer, the force represented by the short line segment is not necessarily smaller than that represented by the long line segment

2. blockchain is a term in the field of information technology. In essence, it is a shared database. The data or information stored in it is characterized by "unforgeability", "trace in the whole process", "traceability", "openness and transparency" and "collective maintenance". Based on these characteristics, blockchain technology has laid a solid "trust" foundation, created a reliable "cooperation" mechanism, and has broad application prospects

from these characteristics, it has a wide range of applications, and it must have good application value.

3. Like weightlifting. It seems that there is no need to do work after stabilization, but in fact it is very hard and can not last long. It's going to consume energy. The reason for energy consumption is that the barbell has a slight up and down movement, so it will need to do work and consume energy. I can only make a qualitative analysis like this, but I haven't thought of how to calculate it.

4. It's actually a matter of volume work, and you should measure it like this: at intervals Δ Two pressure sensors are placed at a distance of 10 s, assuming that time has passed Δ t. The data read on the two pressure sensors are P1 and P2 respectively

and the first pressure sensor is far from the explosion center R. The results are as follows: Δ Volume increment of gas explosion in t time Δ V=4 π[( r+ Δ s)³-r³]/3=4 π( 3r³ Δ s+3r Δ s²+ Δ s³)/3

gas explosion Δ Work done in t time w= Δ P· Δ V=4 π( P1-P2)(3r³ Δ s+3r Δ s²+ Δ s³)/3

power P = w/ Δ t=4 π( P1-P2)(3r³ Δ s+3r Δ s²+ Δ s³)/3 Δ t

5. There is attraction between atoms, that is, universal gravitation
there is repulsive force between atoms, because the electric field force, charge repulsion and electronic action
make the two reach the balance as far as possible, and the sum of the potential energy of these two forces is the smallest

6. Whether an object does work depends on whether it moves a distance in the direction of the force. The other reason you are talking about is that the internal energy increases because of the work done by friction
this needs to be differentiated.

7. The work done is the force multiplied by the distance, and it is the distance in the direction of the force, so the centripetal motion does not do work, because it is vertical,

8. 908.903.619.641.
you can take No.20 bus to Bohai building, and then come all the way
the address is under the overpass of Zhongshan Road North Station in Hebei District.

9.

East station? Is it Tianjin station? Take line 3 and get off at the north station. Just look at the figure below:

10. Bus line 1:
no.651 → NO.901, the whole journey is about 48.5km
1. Walk about 350m from Tanggu Railway Station to the experimental school station
2. Take no.651, pass 8 stations, and reach the stomatological hospital station
3. Take NO.901, pass 10 stations, and reach the North Station
4. Walk about 390m, Get to the fourth Central Hospital of Tianjin

bus line 2:
No.503 → Jinbin Light Rail Metro Line 9 → Metro Line 3, the whole journey is about 49.2km
1. Take No.503 from Tanggu Railway Station, pass 4 stops, and get to the foreign goods market station (also take no.651, no.680, no.835)
2. Walk about 390m to Tanggu station
3. Take Jinbin Light Rail Metro Line 9, After 14 stops, you can get to Tianjin station
4. Take subway line 3, after 3 stops, you can get to North Station
5. Walk about 490 meters to Tianjin Fourth central hospital