A boat moves north at 2.7 m/s across a river that flows east at a rate of 1.2 m/s. What is the boat’s velocity (magnitude and direction angle) relative to the riverbank?

This is the answer: body 1 + engine 2

The radiation of the fire causes the saucepan to heat up. the conduction of the saucepan then to distribute the heat over the saucepan and to give heat to the water. the convection of the water distributing the heat within the water, till all the water is boiling