At what distance will a 80 W lightbulb have the same apparent brightness as a 120 W bulb viewed from a distance of 40 m

Physics

1 answer:

liq [111]3 years ago

4 0

Answer:

32.6mm

Explanation:

Using area of a sphere(bulb) = 4πr²

So A is proportional to radius²

So the Energy will be proportional to r²

But 120/80 = 1.5 is the energy factor so

Using

1.5/d² = 1/r²

1.5/40²= 1/r^2

r = √( 40²/ 1.5)

r = 32.6m

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According to the law of multiple proportions, if 12 g of carbon combine with 16 g of oxygen to form co, the number of grams of c

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The number of grams of carbon that combine with 16 g of oxygen in the formation of CO₂ is 6g.

When two elements combine to make more than one compound, the masses of one element combined with a fixed amount of another element are in the ratio of whole numbers, according to the law of multiple proportions.

When combined with oxygen, carbon can produce two different compounds. They are referred to as carbon dioxide (CO₂) and carbon monoxide (CO).

Carbon monoxide is formed by combining 12 g of carbon with 16 g of oxygen whereas Carbon dioxide is formed when 12 g of carbon reacts with 32 g of oxygen. The amount of carbon is fixed at 12 g in each case. The mass ratio of carbon monoxide to carbon dioxide is 16: 32, or 1: 2.

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