When you have worked out the input of your pulley ( from the newton meter) for different loads, you need to calculate the efficiency. You must then plot a line graph with efficiency up the side and load on the bottom. You then need to describe the pattern and expalin it, and evaluate your experiment.

input = force on newton meter x 3m for a 3 pulley system

output = load (in N) x 1m vertical height

efficiency = output/input x 100%