Một chất chuyển động thẳng đều trên trục Ox với phương trình tọa độ thời gian là x = 80 - 5 t với X có đơn vị là M và t có đơn vị là s a. Tìm tọa độ ban đầu vận tốc của vật và cho biết chiều chuyển động b.tìm tọa độ của vật tại thời điểm t = 10 giây và quãng đường đã đi được trong vòng 10 giây

Các câu hỏi liên quan

Good friendship should base on ____ understanding. A. mutual                            B. selfish                            C. suspicious                D. changeable 2. My friend always helped me out of difficulties. He is very _______. A. hospitable                      B. good-looking                     C. well-dressed          D. helpful 3. Most of the undeveloped countries need a lot of ________ aid. A. together                          B. unselfish                            C. mutual                                 D. friend 4.  He is too ______ to lend me his bicycle. A. selfish                            B. enthusiastic             C. helpful                           D. pleasant 5.  Suddenly she recognized the ______ of the situation that made her laugh. A. wonder                           B. pleasure               C. understanding                      D. hunour 6.  If you want to get a good result in every work, you should have a _____. A. loyalty                            B. sympathy                       C. constancy                D. unselfishness 7. A ______ friendship is a precious relationship. A. mutual                            B. sincere                           C. generous                     D. successful 8.  The children seem to be totally _________ of working quietly by themselves. A. unhelpful                        B. possible                        C. incapable                           D. loyal 9. My brother has ________________ a new interest with enthusiasm.   A. brought up                     B. looked after           C. taken after                      D. taken up 10. Claire has a wide circle of friends and ________________ .           A. neighborhood                 B. acquaintances            C. friendship                      D. relations 11. A person who is concerned only _______ his own interests cannot be a true friend. A. in                                   B. with                               C. for                                  D. about 12. The weather is very ________________ , so you should take an umbrella with you. A. incapable             B. mutual                     C. changeable                          D. unbelievable 13. Can I count on your _______________ to my company? A. trust                               B. caring                  C. understanding                     D. loyalty 14. I can’t stand people with no ________________ of humor.          A. ability                            B. spirit                              C. keenness                                D. sense 15. The local people are very ________________ to strangers.  A. comfortable                    B. hospitable                      C. enjoyable                 D. interested