A rope pulls a rescue sled at constant speed across two sections of snow. The rope acts in the direction in which the sled moves. Across the first section, the rope exerts a force of 90 N for 4.0 m. The sled then moves 8.0 m across the second section. The rope transfers a total of 1000 J of energy across both sections. How much force does the rope exert across the second section?
80 N80\ \mathrm{N}80 N
160 N160\ \mathrm{N}160 N
83 N83\ \mathrm{N}83 N
125 N125\ \mathrm{N}125 N
115 exam-style questions on Edexcel GCSE Physics 8.1 Energy transfers and work, covering 8.1.1 Energy stores and transfer diagrams, 8.1.2 Ways of changing a system's energy, and 8.1.3 Work done by forces. Each one has a worked solution and a mark scheme showing where the marks go.