ok im in high school and have a physics challenge, its a device that transports a mass of 305 grams (Tomato soup can), a distance of 4 meters. no chemical, elastic, spring, electrical or magnetic energy can be used - the only energy source for propelling the device will come from the gravitational potential energy of the soup can. the soup can can be located no higher than 20 cm above the device itself and it will fall down on the device and we are to come up with some form of mechanism to propel the device once the can falls on it. other restrictions are - 1. device has max dimensions of 30cm X 30cm X 30cm 2. nothing falls off the device. if a part detaches and falls on the ground the distance traveled will be measured from starting point to the part. 3. once the device starts to move, it will be self guided and must travel in a straight line. the course is 1 meter wide and if it goes off course, the distance traveled will be from the starting point to where it first went off course. 4. once the can falls, it must not go lower or into the device. so basically it falls and lands on top of device but doesnt go through it to the ground. so... if you have any ideas, please post them. thank you!