The outer surface of a spacecraft in space has an emissivity of 0.8 and a solar absorptivity of 0.3. If solar radiation is incident on the spacecraft at a rate of 950 W/m2 , determine the surface temperature of the spacecraft when the radiation emitted equals the solar energy absorbed.

158.32 K = -114.83 °C

Explanation:

Since P = P' where P = power absorbed and P' = power radiated

P = αAQ where α = absorptivity = 0.3, A = area of spacecraft and Q = rate of incident solar radiation = 950 W/m²

Also, P' = εσAT⁴ where ε = emissivity of spacecraft = 0.8, σ = Stefan-Boltzmann constant = 5.67 × 10⁻⁸ W/m²K⁴, A = area of spacecraft and T = surface temperature of spacecraft.

So, P = P'

αAQ = εσAT⁴

T⁴ = αQ/εσ

T = ⁴√(αQ/εσ)

Substituting the values of the variables into the equation, we have

T = ⁴√(0.3 × 950 W/m²/(0.8 × 5.67 × 10⁻⁸ W/m²K⁴))

T = ⁴√(285 W/m²/(45.36 × 10⁻⁸ W/m²K⁴))

T = ⁴√(6.2831 × 10⁸ K⁴))

T = 1.5832 × 10² K

T = 158.32 K

In Celsius T(C) = 158.32 - 273.15  = -114.83 °C

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s

as we probably am aware that our atmosphere or air have various levels, each level has different gasses, and each gas has another porousness. at the point when the light originates from lower porousness to higher penetrability, it alters its course. with the goal that implies that when the light originates from the moon to the earth, it alters it's course a lot more occasions. it essentially implies that the state of the light piece of the moon is changed on the earth.

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