What is Trebuchet: Definition and 58 Discussions

A trebuchet (French: trébuchet) is a type of catapult that uses a long arm to throw a projectile. It was a common powerful siege engine until the advent of gunpowder.
There are two main types of trebuchets. The first is the traction trebuchet, or mangonel, which uses manpower to swing the arm. It first appeared in China in the 4th century BC. Carried westward by the Avars, the technology was adopted by the Byzantines in the late 6th century AD and by their neighbors in the following centuries.
The later, and often larger and more powerful, counterweight trebuchet, also known as the counterpoise trebuchet, uses a counterweight to swing the arm. It appeared in both Christian and Muslim lands around the Mediterranean in the 12th century, and was carried back to China by the Mongols in the 13th century.

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  1. D

    Static Forces of a Trebuchet

    Homework Statement The goal is to calculate the static forces in the throwing arm of the trebuchet when it's pinned as shown in the image. The counterweight is equal to 1435 Newtons. The mass of the arm is equal to 114 Newtons. Dimensions are shown in inches. The pin is in double shear...
  2. Brandon Preble

    Trebuchet Throwing Arm Optimization

    Summary: Some help would be greatly appreciated for finding the ideal taper and x/y dimensions of a trebuchet throwing arm to optimize strength and minimize the moment of inertia. Long Version: I am a high school junior currently in the process of working on an ambitious project to build a 21...
  3. H

    B Trebuchet Physics: Calculating Baseball Acceleration

    My friend and I are working on a project for our physics class and we need to find the acceleration of a baseball in our trebuchet from rest point to launch point. Does anyone have an idea of an easy way we could find this acceleration.
  4. T

    Simplified Trebuchet Physics: Solving for Omega | Homework Equations

    Homework Statement The trebuchet is a siege engine that was employed in the Middle Ages to smash castle walls or to lob projectiles over them. A simplified version of a trebuchet is shown in the following figure. A heavy weight of mass M falls under gravity, and thereby lifts a lighter weight of...
  5. P

    What direction would torque be on a trebuchet in motion

    What direction would torque be on a trebuchet in motion at the point where the swing arm is parallel to the ground?
  6. P

    What would the Free Body Diagram of a Trebuchet look like?

    What would the Free Body Diagram of a Trebuchet look like (FOR THE SYSTEM)? Would it be comparable to a see saw/ teeter totter? I am aware of some of the forces at play, but I feel there is some I am missing.
  7. K

    Calculate projectile velocity shooting from a trebuchet?

    Hello, I'm designing a hanging counterweight trebuchet for my physics project. I'm wondering if there is any way I can calculate the velocity of the projectile when it is released? (It's shot using a sling attached to the arm) Thanks
  8. lorenzo99

    Angular Velocity of a trebuchet

    Hello, I need some help regarding angular physics. I am working on a project and I want to be able to predict (to some degree) the velocity of the payload leaving the trebuchet. (Excuse my ignorance I am just a high school student) Lets say a trebuchet see diagram has a counter weight m1...
  9. Y

    Build a Tennis Ball Launcher: Trebuchet vs Spring Cannon

    Hey all, I need to build a launcher that is capable of throwing a tennis ball over a 1 meter high wall and hit a target 2 meters away. I realize there are some threads already discussing this, but my question is more based on the type of launcher. Would a trebuchet or a spring powered cannon be...
  10. H

    Work and Kinetic Energy of a Trebuchet

    Homework Statement This time you construct a trebuchet. A counterweight (M = 550kg) is at one end a distance ℓ2 = 1.5m away from the pivot. The child (m = 10kg) is a distance ℓ1 = 3m away from the pivot. The mass of the uniform rod connecting the two is mrod = 35kg. When released from the...
  11. A

    Calculating Trebuchet Mechanics

    Can someone please explain to me how to calculate Trebuchet mechanics? I know it involves lever mechanics with torque, angular velocity and projectile motion but I just can't seem to put these things together.
  12. L

    Why might the two methods of calculating net torque not agree?

    I have a few questions regarding concepts of a trebuchet. I have figured out 3/4 of these questions, and I am looking to ask what you guys think the answers are, or if you can explain the concepts because I do not know if I have even answered the questions right. And the trebuchet is a simple...
  13. G

    Tracking the position of trebuchet payload

    Homework Statement For the parts of the Trebuchet shown, develop expressions for the position, velocity, and acceleration, x, x', and x'' of the payload as a function of the arm angle θ and its derivatives θ', θ''. Use the vector tools in Mathematica to help develop the expressions...
  14. P

    How to calculate the efficiency of a trebuchet?

    Homework Statement Hi, VERY URGENT and I am so confused Find the efficiency of the optimum trebuchet. Optimum trebuchet Specs: Counterweight= 5kg Sling Length= 78cm (laid out fully) Length from fulcrum to load= 44cm Length from fulcrum to counterweight=16cm Height the weight drops...
  15. L

    How to Calculate the Launch Velocity of a Trebuchet Projectile?

    Ok, so for my high school physics assignment i need to analyse the physics of a trebuchet but i need help calculating the velocity at which the projectile would be launched when released, can you please give me a detailed outline of the procedure including all formulas used?
  16. H

    Trebuchet: Projectile Arm Length to Counterweight Arm Length Ratio

    I am working on creating a mid size trebuchet with a projectile arm length of 3 feet. The counterweight is about 3500 grams, with the projectile being 60 grams. I know that the ratio of the projectile arm length to the counterweight arm length changes depending on several factors, most...
  17. G

    Initial Vertical Velocity of a non - horizontal projectile (trebuchet)

    I need to find the initial velocity of a trebuchet launch. Data I have is a distance traveled of 11.1 m, time of 1.25 seconds, height of the sling straight up at 1.85 m. Equations I can use are V2 = V1 + a(t) , dy = V1(t) + 1/2(ay)(t)^2 , V2^2 = V1^2 + 2ad and viy = dy / t. Finding the...
  18. M

    Eccentric rotation of a trebuchet arm

    If the word eccentric is not used correctly, please correct me.Homework Statement I am constructing a mathematical model of trebuchet throw. For the throwing part, I simply use the relation ΔE_p = E_k , so the change of potential gravitational energy goes into the rotational kinetic energy. I...
  19. P

    Question regarding distance traveled by a trebuchet

    Homework Statement I need to find the distance traveled by a trebuchet. We were assigned to design and create one to launch a water balloon of roughly a mass of \approx50 grams. We are not allowed to test it, but must make a prediction of how far it would travel by using physics. The...
  20. J

    Calculating the Centripetal force of a trebuchet

    I need help with calculating the centripetal force of a trebuchet. I have tried to derive an equation from a free body diagram, but I am sure that I'm doing something wrong. Does anyone know how to calculate the centripetal force?
  21. R

    Projectile trajectory - Trebuchet

    Homework Statement Hello, I have an issue regarding projectile trajectory. As an assigment we have made a trebuchet, which is basically a catapult with a sling attached to it. We have done some measurements with the trebuchet itself, and have actually achievement some (according to us)...
  22. B

    Catapulting & Trebuchet Physics: A Beginner's Guide

    I will try and cut to the chase here. My recent hobby involoves variations of catapults and trebuchets. I am finding a need for some physics in rotional mass type situations. I have no background in math beyond basic arithmatic but I have always been pretty good with math logic in a general...
  23. X

    Create a trebuchet that is able to launch a 1ft boulder

    I am attempting to create a trebuchet that is able to launch a 1ft boulder (approximately) 100 yds using a trebuchet mechanism. My current idea is basically to use three 80 lbs bags of cement as the counterwieght and use a sling system at the end of the arm as the launching component. On...
  24. Z

    Finding the speed of a trebuchet

    Homework Statement A simple trebuchet is shown in the figure. Model it as a stiff rod of negligible mass, 2.70 m long, joining particles of mass 73.0 kg and 0.100 kg at its ends. It can turn on a frictionless, horizontal axle perpendicular to the rod and 12.0 cm from the large-mass particle...
  25. K

    Efficiency in trebuchet design

    The medieval trebuchet is a missile-throwing device, with a heavy counterweight on the short end of a beam that pivots about an axle fixed to a supporting frame. A sling is attached to the long end, and when properly "tuned" by adjusting its length, it will release the missile at exactly the...
  26. L

    Floating Arm Trebuchet Calculations and Predictions

    So, like quite a few others on this forum, I am building a trebuchet for a school physics class. While I am really enthusiastic about the project (who doesn't love giant medieval war machines?), I may be a little bit over my head in the calculations. So I hope I can give enough information...
  27. W

    How Much Counter Weight is Needed for a Trebuchet to Hit a Specific Distance?

    Homework Statement We need to find the mass of the counter weight needed to make our projectile go a certain distance. Height = 22.5cm (The height of arm off the ground) Distance needed to travel = 1m/100cm and and 50cm Angle above horizontal = 32 degrees Projectile mass (small ball) =...
  28. A

    Trebuchet problem help >.<

    SORRY if its the wrong place for the topic but I am new >.< hi umm ... I am grade 11 and i got this trebuchet project for school, i built the thing and now i got to do the calculations , i KNOW that mgh( for the counter weight) = 1/2 mv^2 ( for the projectile) but i don't know how to explain...
  29. S

    Calculating Trebuchet Velocity: A Homework Help Guide

    Trebuchet help: Calculating velocity Homework Statement I'm new to this site, so bear with me! OK, so I'm doing a trebuchet for my physics project. I have done three trials with counterweights of different masses. I have all of the distances that a golf ball of mass=0.045kg has traveled. I...
  30. S

    Find Max Speed for Smaller Mass in Trebuchet w/ Stiff Rod & 2 Masses

    Imagine a trebuchet with a stiff rod of 3m and neligible mass.Two masses 60kg and 0.12kg are at its end with the bigger mass 0.14m away from the pivot point. Find the maximum speed the smaller mass attain. Actually i posted this before but it seems i can't get the answer provided in the book...
  31. E

    Trebuchet Help: Calculating Final Velocity & Acceleration

    Trebuchet help! 1. Hi, I am writing a report for a trebuchet project, and trying to find the final velocity of the tennis ball, my teacher told us to just use this :F=m(v^2/r) for initial velocity. so I am really confused right now. I don't know how to find final velocity. Also, which equation...
  32. D

    What is a Suitable Projectile for a Small Trebuchet?

    all I really need right now is a 5 pound small weight that can fit in a spoon but I don't think there is anything that size that can fit in a spoon that would be lying around a house so what is a good projectile for the trebuchet the size of this one which will have a base of 75cm^2 or about 38...
  33. T

    Calculating Power for a Trebuchet: Solving for Projectile Distance and Angle

    Homework Statement This question isn't worth any marks for my school year, I am helping build a small classroom Trebuchet and I don't know where to look for the equations as i haven't really done any physics yet at school. I need to workout the power needed to throw a 20 gram ball 2...
  34. L

    Kwantlen College Science Challenge: Building a Trebuchet

    Hello guys, I got a nice challenge. Myself and some other people at my school are constructing a trebuchet to compete in the Kwantlen College Science Challenge. I've already got ideas for the frame construction, however a few points need to be worked out. Limitations on the device - Must...
  35. K

    Range of Projectile from Trebuchet

    After having set up a trebuchet in my back yard, I decided it would be a fun excersise to predict the range of the projectiles launched. Now, I'm not nearly experienced enough at physics to take into account a hinger counterweight or a sling, so I removed those from the machine.Instead I used a...
  36. Z

    Max Speed of Trebuchet: 24 m/s

    Homework Statement 1. Homework Statement A war-wolf, or trebuchet, is a device used during the Middle Ages to throw rocks at castles and now sometimes used to fling pumpkins and pianos. A simple trebuchet is shown in Figure P8.77. Model it as a stiff rod of negligible mass 3.00 m long and...
  37. H

    Trebuchet Projectile Physics - Height Formula

    Hey guys, this is my first post, so I am sorry if this is in the wrong section. For physics at school, i have built a trebuchet, which stands about 1.2 meters tall, and the arm is about 2 meters long. I have it throwing a projectile easily enough, but for my experiment, i need to find out the...
  38. S

    Solving a Model Trebuchet Problem - Physics Coursework

    (I ignored the template because it didn't really seem to fit my problem, sorry about that) I'm currently doing a coursework assignment investigating the how the range of a model trebuchet varies according to the mass of the counterweight. Its pretty basic stuff (especially compared to a lot...
  39. K

    Trebuchet , rotational K.E.

    Homework Statement A war-wolf, or trebuchet, is a device used during the Middle Ages to throw rocks at castles and now sometimes used to fling pumpkins and pianos. A simple trebuchet is shown in Figure P8.77. Model it as a stiff rod of negligible mass 3.00 m long and joining particles of mass...
  40. L

    How can i find the efficiency of a trebuchet and/or catapult

    I'm doing something for a science fair experiment and I'm trying to compare a catapult to a trebuchet. i will be comparing range, accuracy, and efficiency. But i don't know the equation to find efficiency of each siege wepaon. both of these medieval wepaons will be tabletop size som they won't...
  41. D

    Yr 11 Trebuchet Project Calculations

    Homework Statement I have a physics project in which I need to find a relationship between the distances from each side of the throwing arm of a trebuchet and the actual throwing distances. Let's call the distance from the counter-weight side of the throwing arm to the axle variable 'A'...
  42. S

    Why Is My Trebuchet's Initial Velocity So High?

    ok i had to build a trebuchet for high school and i can't seem to get a decent value for the initial velocity please help. i used a 60 pound counter weight (27.2 kg) a tennis ball to launch (.057 kg) and the counter weight drops about 1.3 m when it is launched i used the equation mgh = 1/2 mv...
  43. M

    Projectile Motion of trebuchet

    Homework Statement I'm looking at trebuchets. Basically, a trebuchet shoots a projectile with an initial velocity of 30ms-1 at an angle of 55, 65 and 75 degrees. Friction/Wind resistance do not account. I need to find the maximum height reached, the time the projectile spends in the air...
  44. M

    Trebuchet, what to look for?

    Homework Statement I've been asked to complete a report on an ancient weapon (Trebuchet chosen) for a final year paper. Basically its to be structured like this: - An introduction including a brief history of the ancient weapon i.e where it was used, why etc. - An explanation of the...
  45. S

    Why Is My Trebuchet Projectile Velocity Calculation Incorrect?

    I was hoping someone out there could offer me much needed insight on my high school Physics project. I had to build a trebuchet and now I have to write a report about it. I have struggled with this and put much time into try to figure the velocity of the projectile (tennis ball) as it leaves the...
  46. T

    Solve Trebuchet Efficiency Mystery

    Homework Statement I've calculated the time, the distance, the height of the counterweight before launch, the mass/weight, and I need to calculate the energy efficiency. How to go about it? h = 0.71 m m = 1.445 kg g = 9.8 m/s^2 t = 0.7 s x = 4.44 m Homework Equations Eg = mgh Vix = x/t y =...
  47. J

    Physics concepts of a trebuchet

    I need to be able to build a trebuchet,write a 15 page technical paper on it, and give a 5 minute speech on the different concepts of a trebuchet. I have never taken physics being a biology kid myself. So therefore I know only very basic physics. I will of course need to do a lot of...
  48. O

    Physics of Trebuchet: Argument with a Friend

    I'm in an argument with a friend of mine. He thinks that a trebuchet's maximum range is directly related to the mass of it's counter weight claiming that all the energy from the counterwiehgt would be transferred to the projectile. I think that it is logarithmicly related because the...
  49. D

    Trebuchet optimizing problem

    hello everyone, I'm new here and i have a few questions about the parameters of a trebuchet. sorry for such a long post. with a simple see saw trebuchet I'm given the projectile weight and counterweight, the length and mass density of the beam, and the height of the support. i am supposed to...
  50. H

    Building a Trebuchet - Seeking Advice on Slings

    hey all, im building a trebuchet and i wanted a litte advice on slings. my trebuchet is about 7 feet tall with a 12 foot arm; i wanted to know if anyone had experience in trebuchets and if they could help me with the sling, or direct me to somewhere with that info. thanks...