How did Eratosthenes measure the size of the Earth quizlet?

How did Eratosthenes measure the size of the Earth quizlet?

Eratosthenes measured the circumference of the earth by measuring the distance between two cities. Then he measured the angle of sunlight relative to the vertical on the summer solstice. The sun was overhead in Alexandria but seven degrees away from the vertical in Syene.

How did Eratosthenes measure the size of the Sun?

Eratosthenes could measure the angle of the Sun’s rays off the vertical by dividing the length of the leg opposite the angle (the length of the shadow) by the leg adjacent to the angle (the height of the pole). This gave him an angle of 7.12 degrees.

What was Eratosthenes method?

Eratosthenes hired a man to pace the distance between the two cities and learned they were 5,000 stadia apart, which is about 800 kilometers. He could then use simple proportions to find the Earth’s circumference — 7.2 degrees is 1/50 of 360 degrees, so 800 times 50 equals 40,000 kilometers.

How did Eratosthenes measure the size of the Earth in 240 BC group of answer choices?

How did Eratosthenes estimate the size of the earth in 240 bc? By comparing whether sun light could reach water down in water wells in two cities at different latitudes and using simple trigonometry.

Who measured the size of the earth?

The Greek philosopher Aristotle (384-322 B.C.) is credited as the first person to try and calculate the size of the Earth by determining its circumference (the length around the equator) He estimated this distance to be 400,000 stades (a stadia is a Greek measurement equaling about 600 feet).

How did Eratosthenes know it was 7 Degrees?

On June 21, 240 BC. Eratosthenes planted a stick vertically in the ground and waited to see if a shadow would be cast at noon. It turned out there was one and it measured about 1/50 of 360 degrees from vertical which is close to 7 degrees.

Who made the first measurement of Earth’s size?

Earth’s circumference was first accurately measured more than 2,000 years ago by the Greek astronomer Eratosthenes, who at the time lived in the Egyptian city of Alexandria.

How do scientist know the size of the Earth?

The most common is to measure the apparent angular diameter of the planet – how big it looks against the sky – very precisely using a telescope. Combining this with a measure of its distance (deduced from its orbit around the Sun) reveals the planet’s actual size.

Who is the first person to measure the weight of Earth?

The first person credited with “weighing” the Earth was Henry Cavendish (1731-1810.) But we must first mention one of the greatest physicists who ever lived – Isaac Newton (1642-1727). Newton’s Law of Universal Gravitation states that any two masses are attracted to one another.

What was Eratosthenes most famous discovery?

Eratosthenes was a Greek mathematician who is famous for his work on prime numbers and for measuring the diameter of the earth.