UNIT: CATAPULT

ACT-Based Writing: Argumentative Writing – The Best Catapult Design

OBJECTIVE:

Students craft a persuasive essay arguing for the most effective catapult design based on data analysis.

Materials Needed:

Data from catapult tests

Research on historical and modern catapults

Writing guide

Student Directions:

Goal:
You will write a persuasive essay arguing which catapult design is most effective for launching projectiles over long distances. Your claims must be supported with historical research and real data from catapult testing.

Step 1: Research Catapult Types

Before writing, learn about the different types of catapults:

Trebuchet – uses a counterweight to swing a long arm

Ballista – works like a giant crossbow, powered by tension

Mangonel – uses torsion (twisted ropes) to launch objects

Research Questions to Guide You:

How does each design work?

What are the advantages and disadvantages of each type?

Which design performed best in your class experiments (distance, accuracy, ease of construction)?

Use both historical research and your class data results to help build your case.

Step 2: Analyze Your Test Data

Use the results from your catapult launches to evaluate:

Which design launched projectiles the farthest?

Which one had the best accuracy or consistency?

How much force was required to operate it?

Record and organize this data in a chart so you can reference it in your essay.

Step 3: Plan Your Essay

Use the structure of a strong argumentative essay:

I. Introduction

Hook: A short, engaging statement to capture interest

Background: Brief explanation of catapults and their use

Thesis Statement: Clearly state which design you believe is the best and why
(Example: “Due to its counterweight efficiency and ability to achieve long-range launches, the trebuchet is the most effective catapult design.”)

II. Body Paragraphs (2–3)
Each paragraph should:

Focus on one reason your chosen design is the best

Include evidence from your test results (e.g., "In our tests, the trebuchet launched a projectile 25% farther than the mangonel.")

Cite historical or engineering research as support

Compare to at least one other design

III. Counterargument

Briefly mention an opposing view (e.g., “Some might argue the mangonel is easier to build…”)

Refute it with reasoning and data (e.g., “…but ease of build does not compensate for lack of range.”)

IV. Conclusion

Restate your thesis in a new way

Summarize your strongest points

End with a closing thought or real-world connection

Step 4: Peer Review & Revise

Exchange essays with a classmate.

Use a writing checklist to check for:

Clear thesis

Logical structure

Evidence-based reasoning

Transitions between ideas

Correct grammar and punctuation

Then revise your draft based on feedback.

Step 5: Class Discussion (Optional)

Be ready to defend your argument in a short class debate or discussion. Use terms like:

Efficiency

Force

Distance

Energy transfer

Accuracy

Engineering trade-offs

Essay Prompt:

Based on historical data and experimental results, which catapult design is the most effective for long-distance projectile launches? Defend your argument with evidence.

ACT-STYLE QUESTION:

Which statement best serves as a strong thesis for an argumentative essay about catapult design?

"Trebuchets were big and cool-looking."

"Catapults are fun to build and use for science experiments."

"Due to their counterweight mechanism and energy efficiency, trebuchets are the most effective long-range catapult design."

"Catapults have been around for centuries and used in many battles."