The topic of today is the energy transfer study using the boat pulley model. The students first built a mimic boat pulley model, then they conducted the experiment to lift load up and record the energy consumption. The students also calculated the energy efficiency of the boat pulley, which is the useful energy divided by the total energy consumption. It is one of the most essential engineering concepts. The STEM information behind this section is the energy transformation between the electrical and potential energy as well as the energy efficiency. All the students finished the model building part. More importantly, they all finished the experiment section and conducted the energy efficiency calculations. They enjoyed the class.