An engineer tests two identical sealed metal boxes for use in a weather station. The coating on one box behaves like a perfect black body. The coating on the other box reflects most infrared radiation.

Both boxes are heated to $∘C90\ ^\circ\text{C}$ and then left in a room at $∘C20\ ^\circ\text{C}$ .

Time in minutes	Temperature of box X in $∘C^\circ\text{C}$	Temperature of box Y in $∘C^\circ\text{C}$
0	90	90
4	70	78
8	55	68

The boxes are then allowed to return to $∘C20\ ^\circ\text{C}$ . Each box is placed the same distance from an identical infrared heater for 5 minutes.

Which box has the coating that behaves like a perfect black body? Explain your answer.

Which box will have the greater increase in temperature during the 5 minutes near the infrared heater? Explain your answer.

Both boxes are heated to $∘C90\ ^\circ\text{C}$ and then left in a room at $∘C20\ ^\circ\text{C}$ .

Time in minutes	Temperature of box X in $∘C^\circ\text{C}$	Temperature of box Y in $∘C^\circ\text{C}$
0	90	90
4	70	78
8	55	68

The boxes are then allowed to return to $∘C20\ ^\circ\text{C}$ . Each box is placed the same distance from an identical infrared heater for 5 minutes.

Which box has the coating that behaves like a perfect black body? Explain your answer.

Which box will have the greater increase in temperature during the 5 minutes near the infrared heater? Explain your answer.

6.3 Black body radiation

Question 38

Markscheme

6.3 Black body radiation

Question 38

Markscheme

6.3 Black body radiation

Question 38

6.3 Black body radiation Questions

6.3 Black body radiation

Question 38

6.3 Black body radiation Questions