View of /trunk/rochester_physics_problib/type16/prob07.pg

    1 
    2    DOCUMENT();
    3 
    4 loadMacros( "PG.pl",
    5                "PGbasicmacros.pl",
    6                "PGauxiliaryFunctions.pl",
    7                "PGchoicemacros.pl",
    8                "PGanswermacros.pl",
    9                "PGgraphmacros.pl",
   10                "PG_CAPAmacros.pl"
   11    );
   12 
   13    TEXT(beginproblem());
   14 
   15 
   16 ## ******************************************
   17 ##
   18 ## Ballistic pendulum
   19 ## By C. Freeman, freeman@NSRL31.NSRL.rochester.edu
   20 ## No unauthorized commercial use.
   21 ## Imported Files
   22 ## ${CAPA_Tools}Problem
   23 ## ${CAPA_GraphicsDirectory}Gtype16/prob07.eps
   24 ## Values needing defined:
   25 ## prob_val (number, e.g. /LET prob_val=1)
   26 ## prob_try (number, e.g. /LET prob_try=5)
   27 ##
   28 ## Last modified 07/21/97
   29 ## by: Patrick D. Freivald, patrick@freivald.org
   30 ##
   31 ## **************************************
   32 ##
   33 $v_bullet = random( 800.0   , 1000.0   , 0.1   )   ;
   34 $m_bullet = random( 5.0   , 15.0   , 0.1   )   ;
   35 $m_box = random( 2.0   , 8.0   , 0.1   )   ;
   36 $m_b_kg = $m_bullet /  1000.0   ;
   37 $h = pow( $v_bullet * $m_b_kg /  ( $m_b_kg  + $m_box    )   , 2.0   ) /  ( 2.0 * $smallg    )   ;
   38 $h_cm = floor( 100.0 * $h   )  + 0.0   ;
   39 $v_bullet_ini = ( $m_b_kg  + $m_box    ) * sqrt( 2.0 * $smallg * $h_cm /  100.0   ) /  $m_b_kg   ;
   40 ##
   41 CAPA_import( " ${CAPA_Tools}Problem " );
   42 TEXT(CAPA_EV (<<'END_OF_TEXT'));
   43 A ballistic pendulum, as shown in the figure, was a device used in the past century to measure the speed of bullets.  The pendulum consists of a large block of wood suspended from long wires.  Initially, the pendulum is at rest.  The bullet strikes the block horizontally and remains stuck in it.  The impact of the bullet puts the block in motion, causing it to swing upward to a height \{ CAPA_tex( '/*h/*'  , 'h'  )  \}.  If the bullet has a mass of \{  spf( $m_bullet    , "%0.1f" ) \} \{ $g_u \}, and the block of mass \{  spf( $m_box    , "%0.1f" ) \} \{ $kg_u \} swings up to a height of \{ CAPA_tex( '/*h/*'  , 'h'  )  \} = \{  spf( $h_cm    , "%0.3f" ) \} \{ $cm_u \}, what was the speed of the bullet before impact?$BR
   44 \{ CAPA_web( ''  , '\noindent {\centerline{\epsfxsize = 1.90 in \epsffile{${CAPA_GraphicsDirectory}Gtype16/prob07.eps}}}'  , '<img src = ${CAPA_Graphics_URL}Gtype16/prob07.gif align=center width=500>'  )  \}
   45 END_OF_TEXT
   46 
   47 ##
   48 
   49 TEXT("$BR$BR",ans_rule(30),"$BR");
   50 ANS( CAPA_ans( $v_bullet_ini   , 'format' => "%0.2e" , 'sig' => '3 plus 13', 'reltol' => 1   ,  'wgt' => $prob_val    ,  'tries' => $prob_try    ,  'unit' => 'm/s'    ) );
   51 ENDDOCUMENT();
   52 #####################
   53 
   54 ###Error: $smallg not defined in this file
   55 ###Error: $smallg not defined in this file
   56 ###Error: $g_u not defined in this file
   57 ###Error: $kg_u not defined in this file
   58 ###Error: $cm_u not defined in this file
   59 ###Error: $prob_val not defined in this file
   60 ###Error: $prob_try not defined in this file
   61 
   62 #####################
   63 
   64 
   65 #################################################
   66 ## Processing time =  1 secs ( 0.62 usr  0.00 sys =  0.62 cpu)
   67 #################################################