View of /trunk/NationalProblemLibrary/270/setDerivatives8RelatedRates/s2_8_7.pg

    1 ## DESCRIPTION
    2 ##  Calculus
    3 ## ENDDESCRIPTION
    4 
    5 ## KEYWORDS('Calculus','Derivatives')
    6 ## Tagged by dgt5v
    7 
    8 ## DBsubject('Calculus')
    9 ## DBchapter('Differentiation')
   10 ## DBsection('Related Rates')
   11 ## Date('')
   12 ## Author('')
   13 ## Institution('')
   14 ## TitleText1('')
   15 ## EditionText1('')
   16 ## AuthorText1('')
   17 ## Section1('')
   18 ## Problem1('')
   19 
   20 DOCUMENT();        # This should be the first executable line in the problem.
   21 
   22 loadMacros(
   23 "PG.pl",
   24 "PGbasicmacros.pl",
   25 "PGchoicemacros.pl",
   26 "PGanswermacros.pl",
   27 "PGauxiliaryFunctions.pl"
   28 );
   29 
   30 TEXT(beginproblem());
   31 $showPartialCorrectAnswers = 0;
   32 
   33 $a1 = random(10,20,1);
   34 $b1 = random(4,8,1);
   35 $c1 = random(30,50,5);
   36 $deriv1 = $b1*$a1/($a1-6);
   37 TEXT(EV2(<<EOT));
   38 A street light is at the top of a $a1 ft tall pole. A woman 6 ft tall
   39 walks away from the pole with a speed of $b1 ft/sec along a straight path.
   40 How fast is the tip of her shadow moving when she is $c1 ft from the base of the
   41 pole? $BR
   42 \{ans_rule(20) \}
   43 EOT
   44 
   45 $ans = $deriv1;
   46 ANS(num_cmp($ans));
   47 
   48 ENDDOCUMENT();        # This should be the last executable line in the problem.