The surface temperature of polaris is about 5973 k. at what wavelength is the peak radiation emitted from polaris?

polaris is not a luminous body. therefore, it does not emit radiation.
550 nm
485 nm
155 nm

The solution would be like this for this specific problem:

Given: 5973 K

λ_peak = 2.898 / 5973 K 

= 0.00048518 mm = 0.48518 μ = 4851.8 Ậ

Polaris emits peak radiation at 485 nm wavelength.

To add, Polaris, commonly the North Star or Pole Star, is the brightest star in the constellation of Ursa Minor. 

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.