1. The problem statement, all variables and given/known data A trolley weighing 16 000kg is moving along a horizontal surface with a velocity od 6m/s. What braking force would cause it to brake on a distance of 10m and how long it would take? 2. Relevant equations a = F/m = ΔV/t 3. The attempt at a solution So ΔV = 6m/s, m=16 000kg, s = 10m and F = mΔV/Δt. We know neither F nor t so how could I solve this? It's just one equation but two unknown variables. Could you please help?