## Self-test 1B.1B

(Wien's law: $T\lambda _{max}=\frac{1}{5}C_{2}$ )

AnvitaaAnandkumar_1B
Posts: 56
Joined: Fri Aug 02, 2019 12:15 am

### Self-test 1B.1B

A red giant is a late stage in the evolution of a star. The average wavelength maximum at 700. nm shows that a red giant cools as it dies. What is the surface temperature of a red giant?

Jiyoon_Hwang_2I
Posts: 101
Joined: Sat Sep 14, 2019 12:17 am

### Re: Self-test 1B.1B

Use the equation T=constant/λ, where the constant is given as 2.9 mm*K (2.9*10^-3 m*K) and λ is 700 nm (700*10^-9 m).
If you plug these numbers into the equation you would get T=(2.9*10^-3 m*K)/(700*10^-9 m)=4.1*10^3 K

AnvitaaAnandkumar_1B
Posts: 56
Joined: Fri Aug 02, 2019 12:15 am

Thank you!