Objects Race 500

Eloise Dillon                  Newton Bateman
                               4214 N. Richmond
                               Chicago IL 60618
                               (312) 534-5055

Objective:

ALL GRADES

To determine how shape affects speed.

Materials Needed:

scale                            hoops
balls                            Various solid disks                            
can of beef broth                can of mushroom soup
Three yardsticks                 Two cans of Comet
Glass jar with lid               construction paper
books or blocks                  A smooth flat board
Clear plastic bottle             Blue food coloring
table                            Four right angle screw clamps
Set of same mass/same size wooden hoop and metal disk (momentum set)
Set of same mass/same size/different distribution sticks (momentum sticks)
           
Strategy:
                          
a.   Set up incline plane.     
b.   Prior to lesson empty one container of Comet into the glass jar and seal 
     the empty Comet container with the lid and set it aside out of sight.  
     Collect twenty objects that roll smoothly from the material listed above. 
c.   Fill plastic bottle half full with water.  Add a few drops of blue food 
     coloring to the water.  Set this aside out of sight. 
d.   Place pair of right angle screw clamps on opposite ends of one yardstick. 
     Place  pair of right angle screw clamps near the center of one yardstick 
     allowing enough space to hold the yard stick between the clamps.  Place the 
     momentum sticks and set on the table off to one side. 
e.   Place scale on the table.  
g.   Make three signs: OBJECTS RACE 500, WINNERS, and NONWINNERS.  Tape the 
     signs WINNERS and NONWINNERS at bottom of the chalkboard tray at opposite 
     ends. 
h.   Make an elimination grid by listing the numbers one through sixteen 
     vertically on the board.  Have children write down names of object next to 
     number on the board.  Start the race by calling children up with their 
     objects.  Place the objects at the high end of the incline plane.  Align 
     the objects behind a yardstick.  Countdown from three to zero.  Lift the 
     yardstick straight up.  Allow the objects to roll down the incline plane.  
     The first object down the incline plane is the winner of that race.  The 
     nonwinning object is to be placed on the bottom ledge by the NONWINNERS 
     sign.  The winning object races the winner of the next race.  Repeat 
     process until all eight races are completed in the first round.  If there 
     is a tie try switching the position of racing the objects.  Race objects 
     back to back.  If one object clearly pulls away from the other that object 
     will be faster.  Ask the children to make observations about the nonwinning 
     objects and do the same for the winning objects.  Repeat the process until 
     all races are completed.  Ask the children to make observations about the 
     winning objects and the nonwinning objects. 
i.   Tell the children that you would like to have some fantasy races with more 
     objects.  Proceed with these pairings for the races: the momentum set, the 
     can of beef broth and mushroom soup, can of beef broth and wooden disk and 
     the last race will be the empty can of Comet and the full can of Comet. 
j.   Ask the children to predict which object do they think will win in each   
     of fantasy races.   
k.   The results will be that the wooden disk will be faster than the metal 
     hoop.  The can of beef broth will be faster than the can of mushroom soup. 
     The empty can of Comet will be faster than the full can of Comet.  The full 
     can of Comet will roll a little distance and then come to a full stop.  The 
     beef broth will beat the metal hoop because the liquid inside is sliding 
     down the incline.  Illustrate this by rolling the bottle of blue water down 
     the ramp. 
l.   Use the momentum sticks.  Swing the sticks out away from your body.  It 
     will be easier to swing the momentum stick that has its mass closer towards 
     the center than the one that has the mass distributed towards the end.  
     This can be illustrated by repeating the swings with the yardsticks.  The 
     yardstick with the right angle clamps near the end illustrates the metal 
     hoop and the empty can of Comet.  The yardstick with the right angle clamps 
     near the middle illustrates solids such as the wooden disks, balls, and the 
     can of mushroom soup. 
m.   Look again at the race between the momentum set(wooden disk and metal 
     hoop).  Show with the scale that both objects have the same mass.  Remind 
     them that the disk was faster than the hoop.  Ask the children to make 
     observations.  Is weight a factor?  No it is not.  The faster objects have 
     a center of gravity closer towards the middle similar to the yardstick 
     with the right angle clamp near the middle.  The hoops have their center of 
     gravity distributed closer to the rim illustrated by the other yardstick 
     with the clamps attached at the end. 
n.   The full can of Comet was the slowest because the powder inside was also 
     turning trying to reach its own center of gravity while the can was       
     rolling down incline.  Illustrate this by rolling the glass bottle of Comet 
     down the incline. 

Performance Assessment:
   
     Rank these objects in the order that they would finish in a fantasy race
     and tell why each object finished in that order.  Use a disk, a can of 
     soda, a hoop and a ball. 

Reference:

    Two hundred and one awesome, magical, bizarre, and incredible 
      experiments by Janice VanCleave.