A cyclist and her bicycle have a mass of 55 kg…

Newton's second law: $F = ma$, where $F$ is the net force. Plan: draw the forces, find the net force, use $a = F/m$, then the equations of motion ($v = u + at$, $s = ut + \tfrac12 at^2$, $v^2 = u^2 + 2as$).