Hi, I'm doing an experiment to get my silver CREST award, in which I've created a mechanical paper plane thrower. I have thrown various types of plane, but all with the same design. The thrower uses a 9V battery, but is more like 6 now. The thrower has two motors, each which take 70mA. The thrower throws consistently with a percentage difference of each throw being <3%, and each plane spends around 0.3s on the launcher before leaving its grasp. My results are as follows: A4 75gsm plane weighing 4.7g travels 4.37m A4 60gsm plane weighing 3.8g travels 3.33m A5 75gsm plane weighing 2.4g travels 3.80m A5 60gsm plane weighing 1.9g travels 2.20m I am trying to find the number of joules each plane takes to get x meters, by finding the j/kg. The j/kg should give me m^2/s^2 which would enable me to work out the power required to throw a 1ton aluminium plane for 1km. However, no matter how hard i try, i cannot get the equation to work for more than 1 value at a time. Can anyone come up with an appropriate equation to work out power or energy from distance, weight and other measurable variables?