Trebuchet help!

  • Thread starter steve092
  • Start date
Trebuchet help: Calculating velocity

1. The problem statement, all variables and given/known data
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 also have the masses of the counterweights.
Just as a starting point for the first trial:
mass of the counterweight=10.937

The average distance for this trial was 34.33m.

2. Relevant equations

3. The attempt at a solution
I've done the calculations; however, my answers were nowhere near what the velocity should be. For one trial, the mass of the counterweight was 10.937kg. I did the calculations and the velocity came out to be 3.53m/s which seemed a little slow.

Obviously, I'm doing something wrong. I wonder if it is because the mass of the golf ball needs to be taken into account somehow??? Anyways, thanks in advance!

I've used the example from and I still can't get it. I don't even understand how the answer was calculated in that example.
Last edited:
Well, I think I might have it! I used that example in the post I linked to in the previous post, and I just changed the values to fit my case. I did the other example to get the right answer that was provided. So, I'm assuming that my answer is correct

Here are the givens:

I used:

And I used the proportion:
v1 .076
-- = --
v2 .838

And just solved for v2.

My final answer was 10.742 m/s which sounds correct, but I'd like to see if I made any mistakes.
That proportion I used, v1/v2= 0.076/0.838, what exactly is that?
OK, I think that solved for velocity correctly. Using the calculated velocity and the average distance traveled of the golf balls in a trial, I calculated a time of about 3.3 seconds. When I launched golf balls and manually timed it, the results were close enough.

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