Determining arm length of catapult

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Homework Help Overview

The discussion revolves around determining the arm length of a catapult designed to project a 2-gram ping pong ball a distance of 1.5 meters. The catapult is identified as a first-class lever, and participants are exploring the principles of torque in relation to this setup.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between torque and the arm length of the catapult. There are questions about the classification of the lever type and the relevance of centripetal acceleration versus tangential speed.

Discussion Status

The discussion is ongoing, with participants clarifying the type of lever and exploring the role of torque in the calculations. Some guidance has been offered regarding the focus on tangential speed rather than centripetal acceleration, but no consensus has been reached on the specific calculations needed.

Contextual Notes

Participants are working under the constraint of not using trial and error to determine the arm length, which adds complexity to their approach.

ArrowHeart
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Hi, I have a big problem...
I got a project on building a catapult. Easy, right? WRONG! We are supposed to determine the arm length without trial and error and I have no clue what to do. Please please help!

Catapult is supposed to be built with 3/4" paper clamp as the only energy source and it must project a 2gram pingpong ball 1.5m. The catapult is a classic 2nd class lever. How would I calculate the arm length?
 
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It's all about torque.
 
ArrowHeart said:
The catapult is a classic 2nd class lever. How would I calculate the arm length?
Don't you mean a 1st class lever? A catapult has the fulcrum in the middle.

AM
 
Sorry, I mis-typed it. It is a first class lever.
How it is torque related? I tried to determine the centripetal acceleration, it didn't work out very well -_-'
 
Last edited:
ArrowHeart said:
How it is torque related? I tried to determine the centripetal acceleration, it didn't work out very well -_-'
You don't need to worry about centripetal acceleration. You are concerned about the tangential speed of the arm, which is a function of the angular acceleration or torque.

AM
 

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