Trajectory ‘08 Dennis Papesh

Goal The team will design, construct, calibrate, and shoot a device capable of launching a ball into a target area, and develop a series of graphs relating launch configuration to target distance and height.

Parameters Launch devices and graphs are to be impounded. Safety goggles must be worn during building, testing, and launching. (see

Construction Launching force must be supplied by non-metallic elastic solids. Must be triggered from outside of the launching area. (No R/C triggers.) Must fit within a 80 cm cube when ready for launching and after launch.

Competition Students will place the device in a launch box 1 meter wide and 1.5 m deep. Once teams are in the event area, they may not leave or receive outside assistance, materials, or communi- cations. DQ

Conpetition continued Students may not touch or hold the device, or be in the launch or target areas during a shot.

Competition continued Students may use weights to hold device in place but such weights must fit within the 80 cm cube. Before and after a shot, all parts of the device must be within the 80 cm cube. Two targets will be placed in a straight line in front of the launching area.

Competition continued Each target will be an approx. 1 meter square box or a 1 meter diameter circle. Each will contain sand or cat litter to mark the impact area. The center of each shall be marked to permit a measurement of the distance of the impact from the center of the target.

Competition continued The center of the target areas will be placed between 2 and 8 meters from the front of the launching area. The two targets must be separated by at least 2 meters. The target areas will be at two different levels with the higher target being nearer to the launch area.

Competition continued The higher target will be up to 1 meter from the floor, in increments of 10 cm. The farther target shall be at floor level. Each team will have 10 minutes to complete 4 shots, two into each of the target areas. (Measurement time not included.)

Typical lane set-up Launch area 2m from line 8m from line Near target Far target either/or Device

Typical lane set-up cont’d

Competition continued Teams must give ample warning prior to a launch. An attempted launch which does not go through a launch motion will not be counted as one of the four launch attempts.

Competition continued Students must inform the event supervisor(s) which target they will be aiming to hit with each launch. Students should, prior to competition, develop and use performance data and calibration charts to determine the best launch parameters.

Penalties – 100 points apiece Student is warned for not properly wearing the safety goggles A participant is in the launch or target area when the launch is triggered No warning given prior to a launch. (Such launch, even if unintended, shall count as one of the four allowed launches.) Any part of device is outside of 1m x 1.5 m launch area during competition.

Graphs Each team starts with 400 graph points which can be reduced by turning in graphs, notes, and other data at impound. Each of 4 selected graphs may reduce the Graph Score by 100 points. Any number of graphs may be impounded but students must indicate which 4 should be used to determine the Graph Score.

Graphs continued Failure to indicate which graphs to score will result in the 1 st four graphs being used. Graphs and tables may be computer generated or hand drawn but must be on separate sheets of paper. If drawn by hand, they must be drawn on graph paper. Data tables must accompany graphs.

Graphs continued Graphs and tables must be properly labeled. All variables and units must be identified. Each graph and data table must be identified with the team name.

Graph Scoring per graph 20 point reduction for completed data table 20 point reduction for graph 20 point reduction if graph matches data table 40 point reduction for graph being properly labeled (title, x & y variables, increments with units, team name) Partial credit may be given

Scoring The winner will be the team with the lowest Final Score. Final Score = lowest Close Target Area Score + lowest Far Target Area Score + Graph Score + Penalties (if any)

Close Target Area Score It shall be the distance in mm from the center of the initial projectile impact location to the center of the target area. Teams who miss the target area will score 700 mm for that shot.

Far Target Area Score It shall be measured similarly for a hit in the target area but measured to the impact location if outside the target area. Supervisor(s) will visually note and mark the observed impact location outside the target area, then measure the distance in mm.

Far Target Area Scores cont’d If the announced target area is the farther target but the projectile hits the nearer target, the score will be a straight line measured distance between the impact location and the center of the farther target.

Scoring Example Lower Close Target Area Score = 10 mm Lower Far Target Area Score = 1487 mm Graph Score = 150 Penalties = 100 Final Score = = 1747

Ranking (tiers) 1 st Tier – Teams who hit both target areas 2 nd Tier – Teams who hit one target area 3 rd Tier – Teams who hit no target area 4 th Tier – Teams who do not meet specifications listed in 3 a, b, c, and/or d.

Tie Breakers 1 st – smallest distance in measurements between the two scored shots (to reward consistency) 2 nd – closer of the two scored shots to center of target area

Devices

More devices

Typical device upright Elastic material Launch arm stopper trigger Maximum of 80 cm Max. 80 cm

Areas to experiment Launch arm – having several holes will allow students to determine the proper ratio of effort force to launch force. Upright – having several holes will allow students to experiment with launch arm height. Upright – being able to move it on the base will allow for experimentation.

Areas to experiment Trigger – something simple, free from jamming, and operates without the need to jerk anything too hard. Non-metallic elastic material – rubber bands? Bungie cords? The material they use to restrict the flow of blood for a blood draw? Plenty of room for experimentation.

Areas to experiment Stopper – having a series of holes will allow students to determine the proper height for the launch arm to stop moving. Length of throwing arm. Distance throwing arm drawn down or back.

Reminder It is up to the students to design, construct, test, and calibrate the device. ‘nuf said on that