An automatic sliding door is opened by a motor. Each time it opens, the motor pulls the door 1.5 m against a steady resistive force of 160 N. During a 2.0-minute test, the door opens 24 times. The motor does no work on the door between openings.
Calculate the mean useful power of the motor during the test.
128 exam-style questions on Edexcel GCSE Physics 8.3 Power and efficiency, covering 8.3.1 Power and 8.3.2 Efficiency. Each one has a worked solution and a mark scheme showing where the marks go.