1)Create a catapult that will toss a projectile onto a target (a small cup) 3 m away using only the supplies provided on the supply list.

2) Determine the initial velocity of the projectile based on measurements.

3)Conduct research of catapults to help refine brainstorm design.

Supplies Allowed:

1)Popsicle Sticks (Max. 24)

2) Straws (Max. 10)

3)String/Yarn (Max 1 meter)

4)Rubber bands (Max 4; Max diameter is 30 cm)

5)1 Dixie Cup (Max 88 mL size)

6)Small Nails (Max 2)

7)Pipe Cleaners

8)Wooden Clothespins

9)Glue  (Glue Stick/Super Glue/Elmer’s/Gorilla – your choice)

10) Masking Tape (Max one roll of 1” width)

11) Paper clips (Max 5)

12) Cardboard (Max 1.0 m2)

13)1 standard cotton ball

 

You must use at least 9 of the items in your design and the supplies must have a function other than decoration.

 

It is recommended you put your catapult in a box/Tupperware for storage/transportation.

1) Your project must not exceed 30 cm in width by 30 cm in length by 48 cm in height at the time of the launch.

2) The catapult must be set and ready to launch in 60 seconds or less (including 2nd & 3rd trial).

3)The catapult must be powered by something other than human force.

4)There must be some kind of trigger to set the launch in motion.  You may not just let go of a string or remove a piece of tape.  The trigger cannot add any additional force to the catapult.  The trigger must be attached to the machine.

5)The distance from the target will be measured from the final landing point (after rolling, sliding, etc.) to the center of the target.  Goal = 3 meters!

6) Any repairs after the first trial must be done within the 60-second window.

7) The group with the smallest combined distance (all three trials included) away from the center of the target wins 5 bonus points.  The group with the second smallest distance away from the center gets 3 bonus points.)  Only groups that fulfill ALL guidelines are eligible for these bonuses.

You will be presenting all of this information to me through the use of a padlet (padlet.com).  

 

Did you use 9 materials?                        ________/5

Is it sturdy?                                          ________/5

Does it have a trigger?                                ________/5

Is it powered by something other than human power?
 
________/5

Does it launch at least one meter?                      ________/5

Does it launch at least two meters?                  ________/5

Bonus?                            ________/5

Drawing/picture/video: (10 points)
Make a neat (ruler) and labeled drawing - must have a top and side view.            
________/4

Video of catapult in action 

________/2

Include dimensions                                      ________/2

Include Materials used                                    ________/2

*Extra credit if done on computer                       
________(2)

Calculations (Lab sheet) (20 points)  Find the time that the projectile is in the air for each of your three launches.

Time 1 
Time 2 
Time 3 
Average

Find the landing distance of all three launches then find the average.

Distance 1 
Distance 2 
Distance 3 
Average

Find the horizontal component of the projectile’s velocity.

v= d/t
Divide your average time by two (2).  This is the time it would take to reach its maximum altitude.

Use this time to determine the maximum altitude of the projectile.

d= 1/2gt²
Use the time for maximum altitude to find the initial vertical velocity.

Vf=Vi+at

Use your two velocity components to find your projectile’s initial resultant velocity.

a²+ b²= c²

Paper (15 points)

1)Provide a brief description of 3 types of catapults: Ballista, Mangonel, Trebuchet.  Explain the good and bad points of each.  Include a picture of each.  Include references using MLA format (for help see www.easybib.com or knightcite.com)  I would expect a paragraph for each type.  Be sure to summarize in your own words. (9 points)

2)Explain how the catapult set the projectile into motion – from the trigger to launch. (3 points)

3)What are three things that you could have done to make the catapult better?  In other words, what are things that could have made your catapult launch the projectile to land closer to the target? (3 points)