I'm going through my end of the year exam papers, since I figured I should actually make an effort at school this year, well anyway I'm terrible at physics and this question stumped me. Heres a diagram ( I drew it in MS paint ha, I even included a helmet cause riding bikes without one ain't safe. ) http://img214.imageshack.us/img214/9627/lolbikemy1.gif [Broken] While travelling home, the bike accelerates at 1.5 ms-2 over a distance of 25m as shown in the diagram. Toni and the bike have a mass of 70kg. (j) Using the equation F = ma, calculate the net force acting on the bike when it is accelerating. (k) If it takes 5 seconds to cover the distance of 25m, calculate the power output of the bike during this time. I think the answer for (j) is F = 70 x 1.5, so this gives me 105 N Anyway I can't remember how I'm suppose to do (k) and my feeble attempts at doing it, gave me 13125 W but I'm sure thats wrong.