Can we hit dings house from here: An exploration into the abilities of potato cannons. By Mike Knippers and Dave Thaler Table of Contents Introduction Method Results Discussion Links Raw Data Return to 01 Projects Results By use of these following physics formulas: v = u + at s = ut + (1/2)at² Ke = (1/2)mv² Pe = mgh We started off by using v = u + at to determine velocity. By cutting time in half, to get to the point at the top where u = 0, from there we are able to calculate the final velocity using gravity and time. 8.36 seconds total round trip. Divide that in half to get 4.18 seconds. Set u = 0 Set up equation v = 0 + (9.8)(4.18) v = 0 + 40.964 v = 40.964 meters / second We then used Microsoft Excel to set up a spreadsheet to automatically calculate the velocity for each data point. Now knowing the velocity, we will be able to calculate the height reached by the potato using s = ut + (1/2)at² Once again, cutting the time in half to arrive at u = 0 s = (0)(4.18) + (1/2)(9.8)(4.18²) s = 0 + 85.61475 s = 85.61475 meters And then setting up a equation in our spreadsheet to calculate height for each data point. Then using Ke = (1/2)mv² and Pe = mgh to determine energy present, using each formula to check the other. Ke = (1/2)(.12)(40.964²) = 100.68 Joules Pe = (.12)(9.8)(85.61) = 100.68 Joules To account for uncertainty we are including the factors of air friction and the ratio of air to hairspray in the combustion chamber. Return to Table of Contents