Suppose a star has the same luminosity as our sun (3.8×1026watts) but is located at a distance of 10 light−years . what is its apparent brightness?

One light year is equal to 9.46*10^15 m. The star is 10 light years away, which is the same as 9.46*10^16 meters. The equation that relates brightness to distance and luminosity (in watts) is brightness = Luminosity/(4*pi*distance^2). The sun has a luminosity of 3.8*10^26 watts (NOT 3.8*1026 watts, as indicated in the problem statement). Using the given distance with the actual implied luminosity of the star: Brightness = 2.8*10^26/(4*3.14159*(9.46*10^16)^2) = 2.49 e-9 W/m^2

Uehejdndndndnndndndjd

Magma forms by partial melting of upper mantle and crust. partial melt means that only a fraction of the available material forms a melt, and that the remainder stays solid. the partial melt rises because of its lower density and ascends through he crust. this is so conclusive mean the answer would be magma igneous rocks or balistic magma.