9. A heater ( of temperature 60C is put at the middle of a straight corridor(E) in a house. It is given that the room temperature in the house without the heater is -6C. Suppose the air temperature is decreased by 2C for every 10 cm away from the heater. (a) What is the air temperature 2.2 m away from the heater? (3 marks) (b) Jessica thinks that 24C is the most comfortable temperature. How far should she stay from the heater? (2 marks)