If the odometer on the car reads 25.0 km at the beginning of a trip and 65.0 km a half hour later, what is the average speed of the car? (remember significant digits.)

Distance covered= 65-25= 40 Km
Time Taken = 0.5 hour

Speed= 40/0.5= 80 km/hr

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