Answer:
The luminosity remains the same, but the apparent brightness is decreased by a factor of four.
Explanation:
The apparent brightness, F = L/4πr² where L = luminosity and r = distance between us and the star.
Since L is independent of the distance between us and the star, it is constant, then
F ∝ 1/r²
So, F₁/F₂ = r₂²/r₁² where F₁ = apparent brightness at r₁ and F₂ = apparent brightness at r₂
If the distance is doubled, that is r₂ = 2r₁, then
F₁/F₂ = r₂²/r₁²
F₁/F₂ = (2r₁)²/r₁²
F₁/F₂ = 4r₁²/r₁²
F₁/F₂ = 4
F₂ = F₁/4
So, since the luminosity is constant, <u>the luminosity remains the same, but the apparent brightness is decreased by a factor of four.</u>
Answer:
50 j
Explanation:
W=Force*distance
W=10N*5M
W=50 NM
n*m = joules so you can say 50joules
Soothing? I don't really know are there any choices?
Since we are only looking at the vertical height, we can use the free fall equation to find the height:
h = 0.5*g*t^2, where h is height in m, g is acceleration due to gravity (9.81 m/s^2), and t is time in seconds
h = 0.5*(9.81 m/s^2)*(3.7 s)^2
h = 67.15 m
Therefore, the 7th floor window is 67.15 m above ground level.
