1. A 500N object is still on the horizontal ground, and the pressure on the ground is - n If the object is subjected to 100N vertical downward pressure, the pressure on the ground is - n 2. People stand on the level ground with both feet. When one foot leaves the ground, people's pressure on the ground -- pressure on the ground——

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• 1. {an} is an arithmetic sequence A3 = 12 S12 > 0 S13
• 2. When the elevator in the mine starts to rise at a constant speed from a standstill, and reaches 4m / s after 5S, it rises at this speed for 20s, then rises at a constant speed, and stops at the wellhead after 4S, then the depth of the mine is______ m．
• 3. As shown in the figure, a computing device has a data input port a and an output port B of calculation results. The following table shows some data input by Xiaoming and the corresponding output results of these data after calculation by the device: according to the calculation rule of this computing device, if the number of input is 10, then the number of output is 10______ ． A 1 2 3 4 5 B 2 5 10 17 26
• 4. We know that the equation kx2 + (2k-3) x + K-3 = 0 for X. (1) prove that the equation always has real roots; (2) when k takes which integers, the two real roots of the equation kx2 + (2k-3) x + K-3 = 0 for X are negative integers?
• 5. Given that there are two points a and B on the number axis, and the distance between the two points a and B is 3, and the distance between the point a and the origin o is 2, then what are all the points B satisfying the conditions
• 6. (make sure you're right!)! 1. It is known that the perimeter of the square is C, the side length of the square is (), and the area is () 2. A travels a kilometer per hour, B travels B kilometer per hour (a + b) × 3 denotes () (a-b) × 5 means () 3. Express the following quantitative relationship by equation (1) M is 9 times more than 38 (2) Three fifths (3 / 5) of 100 m is less than 27:1 (3) M is 78:1 more than one tenth (1 / 10) of 372 5. There are 480 pages in a book. After 8 days of reading, Xiao Fang still has 120 pages left. Suppose that he reads page a every day, then () = 120
• 7. Multiplication and division of rational numbers
• 8. 1 / 2 bracket 1 / 3 (x-1) - 6 bracket = 1 the process of solving equation
• 9. At the Shanghai World Expo, 100 fuel cell sightseeing vehicles were in the Expo site. They drank hydrogen and produced water, realizing zero emission It is necessary to add 30% KOH solution into the fuel cell. Now there are 10kg 10% KOH solution, 14kg KOH solid and proper amount of distilled water. How many kg of 30% KOH solution can be prepared?
• 10. A physics problem about density The mass of a stone is 15g, and the total mass of a glass bottle filled with water is 188g. Now put the stone into the bottle filled with water, and the total mass of the glass bottle is 197g
• 11. The square of 11 to 40 If 11 ^ = 121, the square of 12 = 144, write it out!
• 12. Which number's Square equals 150? Gods help
• 13. The difference between the square of a number and 32 is 32______ ．
• 14. 12345654321 is the square of which number?
• 15. Can the square of a number be zero?
• 16. How to find the square of a number
• 17. The square within 20 is ()
• 18. The product of an integer a and 180 is a square number. When a is the smallest, what is the square number
• 19. If the product of an integer a and 150 is a square number, then a is the minimum
• 20. The product of an integer a and 120 is a square number. When a is the smallest, what is the square number