【英语时差8,16】科学物理测验（上）

 You have a long metal tube that is curved. You also have a miniature golf ball that you are knocking into one end and out the other. How does the ball move after it leaves the other end of the tube? Does it move in a straight line or a curve? Perhaps it starts by moving in a curved line, then gradually straightens out? Or something else? When this question was given informally to a group of undergraduate students, about half of them suspected some kind of curved motion would remain in the ball after it leaves the tube. This, however, is incorrect.