I need to make a car powered only by gravity/a 1kg mass. The 1 kg mass must fall and power the car. No spring, electrical, chemical, elastic etc power. ONLY GRAVITY. The mass and everything else I use, must travel with the car (although I am creating it so the weight drops off once it falls the distance between the top of the car and the ground.) It must travel 3 meters (32 feet). Right now I have a car made from dowels and paint sticks which attaches to 4 “wheels” made from CDs. The axels (round dowels) are inside plastic straws which are glued to the base so that they rotate freely. We added some graphite to help with lubrication and ease of movement. Right now the car only travels about 12 feet. In order to pass the assignment it has to travel at least 25 feet. I’m stuck and don’t know what to do to improve the efficiency of the car and distance it travels. I wonder if the car just weighs too much. I find that once the weight drops and there is no more Pull on the string attached to the axel, the car stops. I’ve viewed many YouTube videos and it appears my car is very similar. I wonder also if perhaps I need to increase the distance the weight drops but it looked like from the equations used on the other posts that a 10 cm drop with a one gram weight is supposed to be enough to propel the car 9.8 meters. I am not getting anywhere close to this distance out of my car. Please note that I have limited knowledge of physics and am not planning on becoming an engineer. The other thread was super complicated when all you super smart scientists decided to have a debate about 3 vs 4 wheels, various size axels, etc. If you have any ideas please help. Thank you.
Edited by Oranjwoman, 10 January 2018 - 10:06 AM.