Physics and Astronomy

Star Wars

To hit as accurately as possible a hidden target with a laser beam reflected from two mirrors.

Participants Teams of up to six.

The judges will provide: the laser.

ii. Student teams must provide:

compass(es), level, masking tape, metre stick, pencils, plasticine, popsicle sticks, protractor(s), spool of string, 2 plane mirrors (maximum reflecting surface 100 cm2 each). Oversized mirrors must be taped so that the reflecting area does not exceed 100 cm^2. 2 mirror supports of team's design. 1 non-reflective path establishing device of team's own design.

Safety CAUTION: Do not look directly into the Laser itself or at a concentrated spot of Laser light!

1. Each team will consist of 6 members. All 6 will line up along the start line to begin the competition.

2. The competition will take place on the floor of a room using a laser beam located 4-6 cm above the floor.

3. The judges will switch on the laser, and shine the undeflected beam at the target. This defines the target spot for the team. The judges will then block the target from the beam.

4. The laser will be run for a time of no more than 30 s to facilitate placement and alignment of a non-reflective path establishing device within the mirror zone. The team may not take any reflecting equipment from the start line while the laser is on. The laser will be switched off on command from the team.

5. As soon as the laser is switched off, a barrier will be placed in the block zone to protect the target from the beam.

6. With the laser off, the team will arrange its two plane mirrors so that the laser beam will be reflected from its starting path, around the barrier and still strike the original target. One mirror must be in the mirror zone.

Visual sighting of the target is prohibited. The purpose of the competition is to measure angles of incidence and reflection accurately.

No member of the team may touch, or come within 0.50 meters of the sending laser or the target. Tape lines will indicate this restricted area. (The intent of this rule is to prevent teams from sighting back from the target and/or running a line from the laser)

7. Teams must be prepared to deflect the beam around barriers up to 2.0 m off the source-to-target line.

8. After a maximum of 3.0 min, time will be called, and alignment of the mirrors will stop. The laser will be switched on, and its new point of impact, relative to the target noted and measured.

9. Teams will take 1 shot each, either to the left or right as assigned at the event.

Judging The Team lines up at the designated area within 1.0 minutes of the call of the Head Judge.
  The Team is fully equipped with all necessary items and ready to compete. No one leaves the area once the team is called and has lined up.
  The Team completes the layout of its equipment in preparation for a shot in no more than 3.0 min, and all team members are back at the start line.
  When the shot is taken, the laser beam hits, in order:
  First mirror
  Second mirror
  Final surface: End wall within 1.00 m of the target
After reflection from the second mirror, the distance from the laser spot to the target will be measured, if it is less than 1.00 m. The team's accuracy score is the sum of the distances obtained from their two attempts. The thirty points allocated for accuracy will be prorated among all teams with two measurable shots.
Penalty Teams with mirrors larger than 100 cm^2 will forfeit twenty points. The excess area must be blocked off with masking tape prior to the competition. -20
Source London District Science Olympics. This event was designed by Dennis Trankner and John Welbourn.
Diagram of the Playing Field

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