English translation When we are reading in the school library, we should keep quiet We should______ the school library_______ when we read books there.

RELATED INFORMATIONS

• 1. Use both hands to pull a spring scale with 10N force at the same time, why is the indication still 10N? I don't understand that. Who knows? Explain
• 2. The two hands pull the spring scale with 6N force respectively. What is the indication of the spring scale?
• 3. What is the indication of both ends of a spring dynamometer with the same force? For example, if two forces are 5N, why is the indicator also 5N instead of adding or subtracting (composition / decomposition of forces)?
• 4. What is the reading of the physical spring Dynamometer when both sides are pulled with 5N force? What is the reading with 10N force on both sides? What is the reading with 5N force on one side without force? Why
• 5. What is the indication when the two ends of the spring dynamometer are pulled by different forces? For example, 5N force at one end and 6N force at the other
• 6. The elevator is suspended with a spring scale on the ceiling, and a small ball is hung under the spring scale. When the elevator moves, the reading of the spring scale becomes larger Then why is the elevator moving downward to make uniform deceleration or upward to make uniform acceleration
• 7. The upper end of a light spring is fixed on the ceiling of the elevator, and an object is suspended at the lower end When the elevator is stationary, the spring elongation is 8 cm; later, it is found that the spring elongation is 12 cm. According to this, the movement of the elevator at this time may be () A. the acceleration is g / 2 B. The acceleration is g / 2 C. The acceleration is 3G / 2
• 8. Hang two balls a and B at the same point o on the horizontal ceiling with two thin wires of the same length, connect two balls a and B with the same length, and then apply force F on ball a, as shown in the figure. At this time, the three thin wires are in a straight state, and ob thin wire is just in the vertical direction, and the two balls are in a static state. Regardless of the size of the ball, the possible direction of force F is zero Xiang Wei () A. Horizontal right B. vertical up C. along o → a direction D. along B → a direction
• 9. On the ceiling, there are four balls with the same electric quantity, a, B, C and D, suspended by insulated thin wires. A and B are negatively charged, C and D are positively charged. They are close to the positively charged object M. affected by the charged body m, the thin wires deflect, as shown in the figure (1) By observing the sacrificial deflection of ball a and ball B, we can draw the following conclusions (2) By observing the sacrificial deflection of the C and D balls of the system, we can draw the following conclusions (2) Compare the string deflection angle of a, B or C, D balls, what rule can you guess?
• 10. As shown in the figure, the two boards are sandwiched in the middle by baffles, and their masses are all m. calculate the friction between them
• 11. Find the rule: what is the number 2003 in the following numbers? What about 2004? What about the nth one? 1，-2，3，-4，5，-6…
• 12. What is the calculation formula of commodity profit rate
• 13. 1. Given that the sum of the unknowns X and Y in the system of equations 3x + 5Y = m + 2 is 0, find the index of M and the solution of the system of equations 2x+3y=m 2. When solving the system of equations ax + by = 21, student a misread the sign of B, so the solution is x = 5 cx+y=19 y=-1 Student B missed C and got the solution x = 3. Try to find the solutions of a, B and C y=2, 3. After a shopping mall bought two kinds of clothes, both of them were sold at a price increase of 40%. During the Spring Festival, it was decided to sell the two kinds of clothes at 20% and 10% discount respectively. A customer paid 182 yuan for the two kinds of clothes, and the sum of the two kinds of clothes was 210 yuan. How much was the purchase price and the price of the two kinds of clothes? How many questions can you answer
• 14. Given that the function FX = 3 ^ x + A / 3 ^ x is even, find the value of A
• 15. Please help to solve the number reasoning problem: 4 7 9 4 25 ()
• 16. How many hectares is 10000 square meters
• 17. Divide the three fourths of a meter long rope into six sections, each of which is a fraction of a meter long
• 18. Comparison of static friction and sliding friction
• 19. Jiugong grid: find the rules and fill in the appropriate numbers 9, 11, 10, 16, (), 12, 17, 8 and 5 in the blank number
• 20. a. B ∈ R, then f (x) = x | SiNx + a | + B is an odd function if and only if () A. a2+b2=0B. ab=0C. ba＝0D. a2-b2=0