## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

(a) $T = 9393.5^{\circ}C$ (b) $T = 693.5^{\circ}C$
(a) We can use Wien's law to find the temperature of the blackbody: $\lambda = \frac{2.9\times 10^6~nm~K}{T}$ $T = \frac{2.9\times 10^6~nm~K}{\lambda}$ $T = \frac{2.9\times 10^{-3}~m~K}{300\times 10^{-9}~m}$ $T = 9666.7~K$ We can express the temperature in $^{\circ}C$: $T = 9666.7-273.15 = 9393.5^{\circ}C$ (b) We can use Wien's law to find the temperature of the blackbody: $\lambda = \frac{2.9\times 10^6~nm~K}{T}$ $T = \frac{2.9\times 10^6~nm~K}{\lambda}$ $T = \frac{2.9\times 10^{-3}~m~K}{3.00\times 10^{-6}~m}$ $T = 966.7~K$ We can express the temperature in $^{\circ}C$: $T = 966.7-273.15 = 693.5^{\circ}C$