what is Catapult
A catapult is a ballistic device used to launch a projectile
a great distance without the aid of explosive devices—particularly various types of ancient
and medieval siege engines
catapult history:catapult is a ballistic device used to launch a projectile
a great distance without the aid of an explosive. Catapults started to be used
in china in the chunqiu period (100BC)ref, while at the same time in Greece
and Italy it wasproven to be one of the most effective mechanisms during wasrfare ref
Type of catapults
Ballista
Springald
Mangonel
Onager
Trebuchet
Couillard
Leonardo da Vinci's catapult
1.Ballista
similar to crossbow
work through torsion
accurate
defectives- immobility and lack in power
2.Springgald
Similar to Ballista
More compact
Anti-personnel weapon
3.Mangonel
Throw heavy projectiles from a ”bowl-shaped bucket”
Anything could be amuniation
Have wheels and easily constructed.
4.Onager
Recreated from magonel design
Limited historical records
5.Trebuchet
Most powerful
2 different designs
Traction- powered by people
Counterweight-power by a weight on the short-end
6.Couillard
simplified trechubet
7.Leonardo da vinci 's catapult
Improve the efficiency and range
No records of this design in real until contemporary
last week we made the catapult
•1. Communication •Listen to others carefully and considering everyone’s ideas. •Choose a suitable contact way for discussing the problem together.
2.Divide the work
•We should divide the work suitably. •We should adjust our work timely, when group member meet difficult problems.
•3.detailed plan •Try to plan more details and obtain a PLAN B. •Plan the time comfortably.
The principle of catapult
The independent variables:
1.Arm Length
2.Counter weight
3.The weight to fire
4.Angle
5.Gravitational force
i. The Arm Length
ii. Angle
&
iii. The Counter WeightThe variables that we could change
