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What is the difference between translation and distance? Please give an example
Firstly, conceptually, displacement is the linear distance from the initial position to the final position of the moving object, and the distance is the motion trajectory. Secondly, displacement is a vector with direction, while the distance is a scalar, only size and no direction
For example, a goes 100 meters to the East and then 100 meters to the west, with a displacement of 0 meters and a distance of 200 meters
Give several examples of applying chemical knowledge in real life? Give four examples
1. When the scale is generated in pots and pans, the scale can be removed by soaking with vinegar
When fish bones get stuck in the throat, drinking vinegar softens the bones
3 the principle of foam extinguisher is applied chemistry knowledge.
The explosion of firecrackers is also an explosion that occurs when some chemicals are mixed in a certain proportion and ignited
Give examples of the application of Archimedes principle in production or life?
1. Bamboo chops
2. Aircraft carrier
3. Submarine
4. Balloons and airships
5. Densitometer
6. Skillfully measuring the density of human blood by buoyancy
7. Salt water seed selection
Examples of using acid-base neutralization reaction in production and life
Absorption of SO2 by ammonia in sulfuric acid industry
Al (OH) 3 is used to treat excessive gastric acid (this drug is not used now)
If it works, give it the best. It's not easy in the middle of the night
Give some examples to illustrate the application of straight-line propagation of light in life
Light travels in a straight line in the same homogeneous medium
1. Small hole imaging (the light of a candle forms an inverted real image in a dark room through a small hole)
2. Shade with a solar umbrella
3. When standing in line, only seeing the first person means that the team is standing together
4. Shadow formation
5. Laser calibration value (used in road construction)
Shadow,
The sunlight from the small hole,
Solar and lunar eclipses,
A three - point line of sight
The beam of the searchlight,
The setting sun shines through the cracks of the clouds,
As shown in the figure, a small ball with a mass of M = 2kg is hung on the smooth elevator wall, and the included angle between the suspension rope and the elevator arm θ= 37 °, then: (1) when the elevator accelerates at As shown in the figure, a small ball with a mass of M = 2kg is hung on the smooth elevator wall, and the included angle between the suspension rope and the elevator arm θ= 37 °, then: (1) When the elevator makes uniform acceleration upward with acceleration a = 0.2g, what is the tension on the suspension rope? (2) If the maximum tension that the suspension rope can bear is 40n, what is the maximum acceleration when the elevator makes uniform deceleration downward? (g) take 10m / S ²）
1.Tcos37°-mg=ma
T can be obtained
2.Tcos37°-mg=ma
Here t is 40
You can find a
RELATED INFORMATIONS
- 1. As shown in the figure, if the length, width and height of the elevator are 1.2m, 1.2m and 2.1m respectively, what is the maximum length of the bamboo pole that can be put into the elevator?
- 2. From the perspective of mechanical stress analysis, how to explain that the rotating tire rolls forward after the car starts? Or how to analyze the relationship between the tire and the ground Stress condition?
- 3. A train moved forward at the speed of 38m / s and whistled 600m away from a tunnel entrance. When the driver heard the echo, how far was the locomotive from the tunnel entrance? (the sound velocity is 340m / s) (do not set the unknown number method to solve, but answer in the way of known, seek and answer.)
- 4. Given log (12) 27 = a, find the value of LG (2) / LG (3)
- 5. The following indefinite integrals are obtained by the first type of substitution method (approximate differentiation method) or the second type of substitution method: 1）∫dx/[x*(x^6+4)]; (1/24)*ln[x^6/(x^6+4)]+c; 2) ∫cosxcos(x/2)dx ; : (1/3)sin(3x/2)+sin(x/2)+c; 3) ∫tan^3secxdx; : (1/3)(secx)^3-secx+c; 4 ∫dx/[x√(x^2-1)]; : arccos(1/x)+c; The answer has been given, please give the process. Do not require all answers, solve one by one
- 6. Proof of differential formula of inverse trigonometric function Complete steps to prove d (arctan x) / DX = 1 / (1 + x ^ 2) The two formulas cos ^ 2 y + sin ^ 2 y = 1 and 1 + Tan ^ 2 y = sec ^ 2 y can be used
- 7. A train advances at the speed of 20m / s and whistles 1800m away from a tunnel entrance. Q: when the driver hears the echo, how far is the locomotive from the tunnel entrance
- 8. A 200 meter long train passes a 1 kilometer long bridge at the speed of 40 kilometers per hour. How long does the train pass the bridge?
- 9. If a 200m long light rail train passes through a 2.8km overpass at a speed of 15m / s, how long does it take for the train to get on the bridge and completely pass the bridge?
- 10. Calculation: a train passes through a 1800m long tunnel at a uniform speed of 20m / s. It is measured that the time required for the train to completely pass through the tunnel is 108s. Calculate: (1) What is the length of the train? (2) How long did the train run in the tunnel?
- 11. Examples of sliding friction, rolling friction and static friction in life
- 12. Which objects are moving in life
- 13. When light passes through a glass plate, its intensity should be reduced by 1 / 10, and the intensity of light should be reduced to less than 1 / 3 of the original. At least such a glass plate; (answer: 11) How to solve it with log?
- 14. Please explain the difference between log and LG and LN, as well as their formulas,
- 15. Log (a ^ k) (m ^ n) = (n / k) log (a) (m) (n ∈ R) how to prove it? Please do not use the bottom changing formula
- 16. The idiom describing water flow, please 3Q
- 17. What is the teaching orientation of symmetry, translation and rotation? How to distinguish symmetry, translation and rotation in life?
- 18. Is the pendulum of a pendulum moving in translation or rotation The sooner the better
- 19. Give some examples of the constant movement of molecules in life The more, the better. A little more detail = = | (just a little more detail.)
- 20. What are the properties of translation and axisymmetry? What about rotation?