Determining arm length of catapult

AI Thread Summary
To determine the arm length of a catapult designed to launch a 2-gram ping pong ball 1.5 meters using a 3/4" paper clamp as the energy source, focus on the principles of torque and angular acceleration. The catapult operates as a first-class lever, with the fulcrum positioned in the middle. The key is to calculate the tangential speed of the arm rather than centripetal acceleration, as this relates directly to the required launch distance. Understanding the relationship between torque and the arm length is crucial for accurate calculations. Properly applying these physics concepts will enable the successful design of the catapult.
ArrowHeart
Messages
3
Reaction score
0
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?
 
Physics news on Phys.org
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
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Angular velocity and acceleration for catapult arm
Replies
4
Views
14K
Solving Catapult Project: Finding Spring Constant
Replies
1
Views
2K
Floating Arm Trebuchet Calculations and Predictions
Replies
2
Views
13K
Find two lowest frequencies standing wave
Replies
5
Views
6K
How to improve the mechanical advantage of a catapult
Replies
2
Views
16K
Initial Velocity for X displacement with air resistance
Replies
6
Views
5K
Fourth Class Levers: Uncovering the Mystery
Replies
2
Views
11K
How Do You Determine Xylophone Bar Lengths for Specific Notes?
Replies
8
Views
12K
*Project* Building electrical (robotic) arm. Need help
Replies
5
Views
9K
I Yet another spacetime-bending layman question
Replies
8
Views
2K

Hot Threads

Recent Insights

Back
Top