Superman is flying 54.5 m/s when he sees a train about to fall into a river 850 m away. he must reach the train in 4.22 s. what acceleration does he need? (unit = m/s^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

The correct answer is waves