[physstudent1]

Hello all,

I'm working on a project for a competition with some peers, where we have to make a car that runs on a chemical reaction and stops on one.  I'm on the team making the stopping mechanism.  Currently our ideas are either an iodine clock or a magnesium acid drip, I was wondering if anyone here has some ideas on what we could use to make the car stop at the required distance! Thank you .

[nj_bartel]

Break system that is powered by air pressure; chemical reaction that evolves gas

[physstudent1]

that is a great idea thanks!