$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 5
If a runner is running at a constant speed in a race, and then speeds up to twice his previous speed in the last few seconds of the race, which of the following velocity-time graphs best describe his motion?
