A 120m long train passes through a 300m tunnel at a speed of 14m per second, counting from the moment when the locomotive enters the tunnel

RELATED INFORMATIONS

• 1. Given that the image of function f (x-1) is symmetric to the image of function g (x) with respect to the straight line y = x, and G (1) = 2, then a, f (1) = 1 B, f (2) = 1 C, f (3) = 1 D, f (0)= Given that the image of function f (x-1) is symmetric to the image of function g (x) with respect to the straight line y = x, and G (1) = 2, then a, f (1) = 1b, f (2) = 1C, f (3) = 1D, f (0) = 2
• 2. If the function f (x) = (2 ^ x-1) / (2 ^ x + 1) and the image is symmetric with respect to the line y = x, then G (1 / 3)=
• 3. If the image of the function f (x) = 3x + B and the image of the function g (x) = x / 3-1 are symmetric with respect to the line y = x, then the value of B is equal to?
• 4. Given the function f (x) = sin ω x + ACOS ω x, the image is symmetric with respect to the line x = π / 6, and the point (2 / 3 π, 0) is a function graph
• 5. Given that f (x) = sin ω x (ω > 0), if y = f (x), the minimum distance from a symmetry center to the symmetry axis is π / 4, try to write the analytic expression of the function
• 6. If the image of the function y = ACOS (x − π 6) sin (ω x + π 6) (a > 0, ω > 0) is shifted to the left by π 6 units, the image obtained is symmetrical about the origin, then the value of ω may be () A. 2B. 3C. 4D. 5
• 7. F (x) = sin (x + π / 3), the image of F (x) is symmetric with respect to (- 1,0), and the function is?
• 8. Given that the image of the function f (x) = 2Sin (ω x + φ) (ω > 0) is symmetric with respect to the straight line x = π 3 and f (π 12) = 0, then the minimum value of ω is () A. 2B. 4C. 6D. 8
• 9. Given that the image of the function f (x) = 2Sin (Wx + π) is symmetric with respect to the line x = π / 3 and f (π / 12) = 0, what is the minimum value of W
• 10. Let p be a center of symmetry of the image c of the function f (x) = sin ω X. if the minimum distance π 4 from P to the axis of symmetry of the image C, then the minimum positive period of F (x) is () A. 2πB. πC. π4D. π2
• 11. Eight identical rectangular tiles are used to form a rectangular floor. The tiling method and relevant data are shown in the figure. The length and width of each tile are calculated
• 12. There are some children in the kindergarten. Mr. Li took 32 pieces of chocolate and gave them an average, just finished. What is the number of children
• 13. In diamond ABCD, CE is perpendicular to AB, e is perpendicular, BC = 2, be = 1, find the perimeter and area of the diamond
• 14. A mathematical problem about merging similar items ① Known polynomial ax's cube + ax's Square - 2x's cube + 2x's square + X + 1 is a quadratic polynomial about X, find the value of a's square + 1 / A's square + a! ② Try to explain that the sum of any three consecutive integers must be a multiple of 3
• 15. As shown in the figure, in the rectangular coordinate system, let a (3,2) B (4,1) C (m, 0) d (n, n) be the four vertices of the quadrilateral. When the perimeter of the quadrilateral ABCD is the shortest, the value of M, n is the same
• 16. 50 calculation problems of linear equation with one variable It's a little harder
• 17. As shown in the figure, in the parallelogram ABCD, ab = 10, ad = 6, e is the midpoint of AD, take a point F on AB to make △ CBF ∽ CDE, then the length of AF is () A. 8.2B. 6.4C. 5D. 1.8
• 18. Ask people to teach edition seven grade two mathematics page 47-48 answer, thank you
• 19. If a certain commodity is sold at a discount of 7.5% of the price, it will lose 25 yuan, and if it is sold at a discount of 9% of the price, it will make a profit of 20 yuan. What is the price of the commodity and what is the purchase price?
• 20. Mathematics final paper of grade one 8. If the ratio of the two angles is 7 ∶ 3 and the difference is 72 degrees, the relationship between the two angles is () (A) Equality (b) mutual complement (c) complementarity (d) cannot be determined 9. The charging standard of a taxi is: the starting price is 6 yuan (i.e. the driving distance is less than 3 km, you need to pay 6 yuan). After 3 km, you will be charged 1.5 yuan for every additional kilometer (less than 1 km is counted as 1 km). Someone will pay 18 yuan for taking this kind of taxi from place a to place B. if the distance from place a to place B is 1 km, the maximum value is () （A）7 （B）9 （C）10 （D）11 10. Party A and Party B each use a square piece of paper ABCD to fold a 45 ° angle (as shown in the figure), and their methods are as follows: A: fold the paper along the diagonal AC so that point B falls on point D, then ∠ 1 = 45 °; B: fold the paper along am and an so that B and D respectively fall on a point P on the diagonal AC, then ∠ man = 45 °. For the two people's practice, the following judgment is correct () A) Both a and B are right (b) both a and B are wrong (c) both a and B are wrong (d) both a and B are wrong