1. What have I done wrong when I set this GCSE question?! (shortened) Gravity: 10 N/kg Bowling ball: weight 10 N, air resistance 0.05 N, overall force 9.95 N Football: mass 0.5 kg, air resistance 0.05 N Students need to work out: effective force on the football (4.95 N) bowling ball (a = F/m = 9.95 / 1 = 9.95 N/kg) football (a = F/m = 4.95 / 0.5 = 9.9 N/kg) So... what have I messed up as I'm pretty sure their acceleration should be equal!? 2. Relevant equations F = ma, W = mg 3. The attempt at a solution I have played around with it and I'm missing something, help!