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Juliette [100K]
3 years ago
9

An extraterrestrial "Eratosthenes" performs the equivalent experiment, that Eratosthenes did on Earth, on her/his home world. Sh

e/He measures the angle of the shadow in her/his alien hometown (Alexandria) to be 10 degrees and the distance to the alien well (Syene) to be 500 km. What is the radius that the alien Eratosthenes estimates for her/his planet?
a. 2865 km
b. 9065 km
c. 18024 km
d. 1500 km
e. 31415 km
Physics
1 answer:
Bad White [126]3 years ago
6 0

Answer:

a. 2865 km

Explanation:

Eratosthenes observed that the sun's rays formed a vertical angle of 7º 12 ’. Which confirmed that the Earth was not flat, assuming that it had a spherical shape, using the distance between Alexandria and Siena and the measure of the angle of inclination of the solar rays in Alexandria, calculated the circumference of the Earth.

The calculation was made with a simple rule of three:

angle of inclination of the solar rays——————- distance

               360º                                   ————- Planet circumference

C=\frac{distance*360^\circ}{angle}\\\\C=\frac{500km*360^\circ}{10^\circ}=18000km

And since we know that:

C=2\pi R\\\\R=\frac{C}{2\pi}\\\\R=\frac{18000km}{2\pi}=2865km

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sp2606 [1]
The diagram is in the picture attached.
Options are:
A) 32 °C
B) 70 °C
C) 92 °C
D) 100 °C

In order to find the value required, you need to look at the diagram and follow these steps:
1) search for the value of 70 kPa on the y-axis;
2) move on a horizontal line towards the right until you reach the line D;
3) move on a vertical line down, towards the x-axis;
4) read at what value of °C you are at.

Doing so, you can see that you are at a value a little bit above 90 °C (see picture).

Hence, the correct answer is C) 92°C.

5 0
3 years ago
Which of the following is not true about elements.
alexgriva [62]

Answer:

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Explanation:

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8 0
2 years ago
A stone is thrown straight up from the ground with an initial speed of 44 m/s.At the same instant, a stone is dropped from a hei
Lubov Fominskaja [6]

Answer:

394.26 m

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration due to gravity = 9.8 m/s²

v=u+at\\\Rightarrow 0=44-9.8\times t\\\Rightarrow \frac{-44}{-9.8}=t\\\Rightarrow t=4.49 \s

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s=ut+\frac{1}{2}at^2\\\Rightarrow 98.77=0t+\frac{1}{2}\times 9.8\times t^2\\\Rightarrow t=\sqrt{\frac{98.77\times 2}{9.8}}\\\Rightarrow t=4.49\ s

Total time taken by the stone to reach the ground is 4.49+4.49 = 8.97 seconds

s=ut+\frac{1}{2}at^2\\\Rightarrow h=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{h\times 2}{9.8}}

The times are equal so,

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3 years ago
Which of the following describes resistance force?
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4 0
3 years ago
Read 2 more answers
A red light, green light, and blue light differ in A. amplitude. B. complexity. C. wavelength. D. purity.
Sindrei [870]

Answer:

A red light, green light, and blue light differ in wavelength

Explanation:

A red light, green light, and blue light differ in wavelength .

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6 0
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