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jayrey wrote:help finding ratios!!

So I'm new to the compound machines event. I made my second class lever, much like the pictures from the previous posts (one bar higher than the other, connected by a string).

I'm getting consistent results but I don't know how to find the ratios? Is there a mathematical way to do it or measurements that I need to make? I can't figure it out. Please help!!

I think there was a post about it earlier on the thread.

Unome wrote:

jayrey wrote:help finding ratios!!

So I'm new to the compound machines event. I made my second class lever, much like the pictures from the previous posts (one bar higher than the other, connected by a string).

I'm getting consistent results but I don't know how to find the ratios? Is there a mathematical way to do it or measurements that I need to make? I can't figure it out. Please help!!

I think there was a post about it earlier on the thread.

Here are links to blindmewithscience's explanation and my explanation.

bernard wrote:

Unome wrote:

jayrey wrote:help finding ratios!!

So I'm new to the compound machines event. I made my second class lever, much like the pictures from the previous posts (one bar higher than the other, connected by a string).

I'm getting consistent results but I don't know how to find the ratios? Is there a mathematical way to do it or measurements that I need to make? I can't figure it out. Please help!!

I think there was a post about it earlier on the thread.

Here are links to blindmewithscience's explanation and my explanation.

I found it after I posted. Thanks so much!! On another note, can we have our apparatus setup at the edge of the table so that the mass hanging down from the second class lever is hanging below the Lowest edge of the apparatus?

jayrey wrote:

bernard wrote:

Unome wrote:I think there was a post about it earlier on the thread.

Here are links to blindmewithscience's explanation and my explanation.

I found it after I posted. Thanks so much!! On another note, can we have our apparatus setup at the edge of the table so that the mass hanging down from the second class lever is hanging below the Lowest edge of the apparatus?

I don't see any restrictions against it in the rules, so it should be allowed in my opinion. You could avoid having it hang lower by making the fulcrum of your levers higher since there isn't a device size restriction (just a restriction on the length of each lever), but I don't think it's necessary if you've already made your device since what you described should be allowed.

jayrey wrote: I found it after I posted. Thanks so much!! On another note, can we have our apparatus setup at the edge of the table so that the mass hanging down from the second class lever is hanging below the Lowest edge of the apparatus?

Though let me play the role of the mean event supervisor: Does your device work without the table? If not, did you impound the table? What if the supervisor is having you do this on the floor?

Just better to do what bernard suggested and elevate your fulcrum.

davidkim2106 wrote:OH!!! So what kinds of hooks would they be? Pictures would be awesome. Also, our lever doesn't seem to work, we use the right equation, but when we hang them directly (and then connect the two levers together with a string), our ratios are always off for some reason.

Any ideas? Thanks guys

Our team connected 2 zipties around the lever and then added a wire-like thing (that's not really like wire, but can bend and is strong, sorry for the REALLY bad explanation of what it is..) to the bottom of the ziptie so that it closed around the ziptie on one end and had a little U on the other end for you to hook the mass on.

GoldenKnight1 wrote:

jayrey wrote: I found it after I posted. Thanks so much!! On another note, can we have our apparatus setup at the edge of the table so that the mass hanging down from the second class lever is hanging below the Lowest edge of the apparatus?

Though let me play the role of the mean event supervisor: Does your device work without the table? If not, did you impound the table? What if the supervisor is having you do this on the floor?

Just better to do what bernard suggested and elevate your fulcrum.

You could alternatively make your lever arm shorter if possible. That way, you are less likely to hit the table.

jayrey wrote:On another note, can we have our apparatus setup at the edge of the table so that the mass hanging down from the second class lever is hanging below the Lowest edge of the apparatus?

You could also prevent it from going down that far by putting some sort of stop on the lever. We implemented ours in the form of two nails 1" above and below the right side of our class 1 lever. That way, the lever couldn't go above or below balanced position by more than a few inches. This did create the need for a "quicker eye" when adjusting the lever but we came up with a solution for that as well - which I will share after all competitions are over.

Anyone have any pictures of their device?

davidkim2106 wrote:Anyone have any pictures of their device?

You could go in the image gallery.