Use the diagram to answer question; Camphor is a chemical that sub-limes and interacts with water reducing the surface tension where it is put. Explain why ...

Use the diagram to answer question;

Camphor is a chemical that sub-limes and interacts with water reducing the surface tension where it is put. Explain why the toy boat illustrated above would move forward with the camphor placed at the back of it but would be stationary before the placement of the camphor.