Junkyard Challenge C

[Untitled]

So both the device and tools to modify it have to fit in the same box right? At state are you allowed to bring 2 different box for the 2 different devices? Or do both of the devices have to fit in one box?

[rockhound]

So both the device and tools to modify it have to fit in the same box right? At state are you allowed to bring 2 different box for the 2 different devices? Or do both of the devices have to fit in one box?

1 paper-size box with the parts for your device (both devices at states)
plus any other tools you would like to bring to help you build the device but cannot be part of the device

[RenaissanceLady]

How accurate are you guys getting your coin sorters? Ours is pretty good for quarters and nickels, but dimes and pennies are a mess.

[Untitled]

How many people at your regional were using mechanical devices compared to electronically calibrated at your regional?

[Culebra54]

[quote="Uncle Fester"]Ran Junkyard yesterday. 160.8g mass (cookies), with the best score being MUCH less than one.

One team built a digital inertial scale that required a calculator to determine the correct mass; clearly student designed and built (one of the more intelligent conversations I had all day), and was off by a half gram, but it didn't win-- it was beat by a spring arm scale that was almost 2m wide and 1m tall.quote]

Was the official mass of the Challenge Object determined by weighing in air? With competitors achieving the levels of accuracy and precision you describe, the bouyancy effect becomes important. For a challenge object with a specific gravity of 1, the bouyancy effect results in a scale reading which underestimates mass by roughly 0.12% (0.2 g for a 160 g CO). The error increases as the density of the CO decreases.

Official masses at Nationals last year were measured on a scale in air and then adjusted to account for buoyancy.

[jazzy009]

our coin sorter is good. nothing gets messed up, the only problem we will have at states is if they give us like 300 pennies...which they probably will

[call4angel]

hey!
my teacher randomly signed me up for this event today and he told me to make a scale by saturday. is it even possible???

anyways i had a few questions...ill be REALLY grateful if you answer it!

1. To figure out the mass of the object the judge gives us can we just multiply the previously determined spring constant and the change in length?

2. Does that measuring of the length make it non-autonomous?

i am really confused and frustrated....please help me!!!

[maggymay]

hey!
my teacher randomly signed me up for this event today and he told me to make a scale by saturday. is it even possible???

anyways i had a few questions...ill be REALLY grateful if you answer it!

1. To figure out the mass of the object the judge gives us can we just multiply the previously determined spring constant and the change in length?

2. Does that measuring of the length make it non-autonomous?

i am really confused and frustrated....please help me!!!

Man that truly *sucks*. Best of luck though, sorry I'm probably not going to be much help with your planning.

When we asked what exactly an "autonomous device" was, we were told it has to operate without any human intervention. I'm not quite sure what your 2nd question means . I think you might have to test it to see how far the spring goes for the weights and then make a home-made graph with the weights(lengths) marked on it. From my understanding having an independent graph/system of measurement doesn't make the actual device NON-autonomous.

[trombonegirl23]

My competition is Saturday and my partner and I haven't had time to start this yet...i'm sure we will do good

[jazzy009]

use a spring, all your troubles will be over. it is definitely possible, i was put in a spot like yours earlier this season, for an invitational we made a spring scale the night before and managed 3rd place. it is definitely doable. but obviously, if its a regional, you wont get as high, but you can still do decently