2 years ago

Please help me! With question 1 and 2 really need help please

Biology

1 answer:

Serjik [45]2 years ago

5 0

One is 2nd and 2 is 4th one

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An owl has good night vision because its eyes can detect a light intensity as small as 5.0 × 10-13 W/m2. What is the minimum num

Lady bird [3.3K]

Answer:

Thus, the minimum number of photons per second is 77.34

Explanation:

Light intensity, $I_{min}$ = $5\times 10^{-13} W/m^{2}$

Pupil has a diameter, d = 8.5 mm

= 8.5 x $10^{-3}$ m

Radius of the eye, r = 4.25 x $10^{-3}$ m

∴ Area of the eye, A = $\pi .r^{2}$

= $3.14\times \left ( 4.25\times 10^{-3} \right )^{2}$

= $5.6\times 10^{-5} m^{2}$

Let $P_{min}$ be the minimum number of photons.

Therefore, $P_{min}$ = $I_{min}$ x A

= $5\times 10^{-13}$ x $5.6\times 10^{-5}$

= $2.8\times 10^{-17}$ W

Thus the minimum number of photons is given by

$N_{min}=P_{min}/E$

where E = $hc/\lambda$

= $\left (6.63\times 10^{-34}\times 3\times 10^{8} \right )/548\times 10^{-9}$

= $3.62\times 10^{-19} J$

Therefore, $N_{min}$ = $\frac{2.8\times 10^{-17}}{3.62\times 10^{-19}}$

= 77.34 photons per second

Thus, the minimum number of photons per second is 77.34

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3 years ago

Which natural resource does Australia produce more of than any other country in the world? oil natural gas gold bauxite

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The correct answer is gold. That's why it has reserves of almost 10 000 tonnes of gold which accounts to almost a fifth of the entire world gold reserves. It is way ahead of the second placed South Africa that produces only 6 000, and Russia that does 5000. It has been going down in recent years, but it's nothing significant and will likely stay first for years to come.

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