$answer){ //Check the answer hasn't already been submitted. $testQuery=mysql_query("select count(id) as c from ".$mysqlAnswerTable." where sn=".$_SESSION['sn']." and question=".$question); if(mysql_error()){ echo "Please report this to the administrator: ".mysql_error(); die; } if(mysql_result($testQuery,0,'c')!=0) {mysql_close(); header("location:".$nextQuestionURL); die(); }; $query="insert into ".$mysqlAnswerTable."(sn,course,question,answer,tstamp) values('".mysql_escape_string($_SESSION['sn'])."','".mysql_escape_string($_SESSION['course'])."',".$question.",'".mysql_escape_string($answer)."',".time().")"; mysql_query($query); if(mysql_error()){ echo "Please report this to the administrator: ".mysql_error(); die; } } //Go to the next question. mysql_close(); header("location:".$nextQuestionURL); die(); } else if(isset($_POST['Submit'])) $flag=1; ?> Question 7
Question 7



If a person were to start off next to a motion detector and then move forwards and backwards repeatedly at a constant speed, which of the following position-time graphs would best describe their motion?



A.
B.
C.
D.
None of these graphs are correct.

  A B C D
Answer