If the laser pulse width is 100 fs, estimate the energy spread (in mev) of the pulse using at δω ~ 1, and the corresponding and 500nm. at 800nm

Did you ever figue this

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

Velocity is the speed of an object in a certain direction so you'd need to know speed and direction