Physics Project

[Matt]

Hey everyone, I've got a physics project due soon, and I'm really stumped on what to do. The general idea is to construct something that will move exactly 8 meters. Here are the specific rules:

1. The device must be in a ready to go position (but not moving) with no one touching it.

2. Movement must be initiated by a dropped weight.

- The weight could directly strike the device, hit a button, or do anything else to make it go.

3. There will be a golf ball on the front of the device. At the end of your trial the golf ball must remain at the front of the device. The golf ball must stay on the device.

4. You can only use a remote control vehicle if you are not steering/driving it with the remote (example: you could attach the remote to the vehicle, and some how have it in the on position).

5. No parts of the device, or parts that influence the device, may be past the start live before the start of the trial.

6. The device, after crossing the start line, can not be connected to anything behind the start line (example: you can't tie 8 meters of rope to your device and the other end tethered to a wall) Exception: extension cords will be allowed on both sides of the start line, provided the cord does not act to stop the device.

7. No animals

8. The start line will be the front end of your golf ball or the end/bottom of a ramp (if you choose to use a ramp).

9. The finish line will be the front of your golf ball when the device has completely stopped.

To get an A, I have a margin of error of 7.90 meters - 8.09 meters if I use a ramp, and 7.85 meters - 8.09 meters without a ramp.

There is a wall at 8.10 meters, and if any part of the device hits that wall, the trial counts as a failure.

Now, like I said, I am very stumped on how to do this. My first thought was to take a toy car, and let it drop down a ramp. As the tires spin, a string wrapped around one axle will unravel and wrap around the other axle. Once it has done that, the axles will lock, and theoretically stop the car. Unfortunately, I am not having much luck with this idea.

If anyone has any thoughts/ideas please let me know!!

[bozodog]

I was thinking the same thing about a string 8 m long. How about a motor from Legos to wind up the string? Doesn't Legos make a powered car kit?

Good luck!

[bozodog]

I was thinking the same thing about a string 8 m long. How about a motor from Legos to wind up the string? Doesn't Legos make a powered car kit?

Good luck!

Yep, they do

[echobay]

Hey Matt..Just wanted to say HI..And good luck with THAT!

my brain hurts..The dog ate that page..i think like a 5th grader..

Edited November 28, 2007 by echobay

[Pete_C]

Can golf ball be glued to device?

If so, I too support the weight / rope approach but with the note that you will want to have it turn a wheel which drives the drive wheel.

Traction is a must and calculating the length needed to go the distance is needed.

one approach would be to make the wheels a set circumference and then have it advance a gear one notch each revolution. When the desired number of revolutions is reached then the gear trips a brake/ lock to prevent it from going further.

Or can it be anchored? Then have a tether measured precisely (remember to take into account the length of the cart ) so that when it is fully extended it will stop forward advance. Then just use a spring or weight / string or electric motor to propel it forward until the anchor stops it at the right point.