A cable drive pulls a model sliding gate along a straight horizontal track. After starting, the gate moves at a steady speed.

A student has a force sensor that measures the tension in the cable, a tape measure, marker strips and a stopwatch.

Describe how the student could determine the useful power delivered by the cable drive while the gate is moving at steady speed.

Your answer should include how the apparatus should be arranged, the readings that should be taken and how the readings should be processed.