Question

1. how did people first determine that the earth was a sphere?

a. by watching the sun set below the horizon
b. by taking pictures of the earth from a satellite in outer space
c. by observing the shadow of the earth on the moon during an eclipse
d. by seeing an apple fall out of a tree

1. a pencil and a leaf are dropped from the same height at the same time. which best explains what will most likely happen and why?

a. the pencil will hit the ground first because it has a stronger gravitational pull than the leaf.
b. the pencil will hit the ground first because the leaf is slowed down by air resistance.
c. the leaf will hit the ground first because it weighs less than the pencil.

1. which word could best replace the word myth in the passage?

a. fact
b. legend
c. detail
d. description

1. what is the most likely meaning of the root astro - in the word astronomer?

a. apple
b. man
c. stars
d. moon

1. which statement about gravity is true?

a. there is no gravity on the moon.
b. gravity was invented by isaac newton.
c. lighter objects have more gravity than heavier objects.
d. gravity is what causes planets to be spherical

Explanation:

1. Question 1:

• Option a: Watching the Sun set doesn't prove the Earth is a sphere. It could be a flat surface with the Sun moving away.
• Option b: Satellite pictures are a modern way, not the first.
• Option c: Observing the Earth's shadow on the Moon (during an eclipse) shows a curved (spherical - like) shadow. This was an early method.
• Option d: An apple falling relates to gravity, not Earth's shape.

1. Question 2:

• Option a: Gravitational pull depends on mass and distance. If same height (distance from Earth's center is almost same), but air resistance is the key. Pencil is more streamlined.
• Option b: The leaf has a larger surface area (relative to its mass) and air resistance slows it more.
• Option c: Weight (less than pencil) is not the reason. If no air resistance, they would fall at same rate.

1. Question 3:

• Option a: "Fact" is the opposite of "myth".
• Option b: "Legend" is a traditional story (often with some fictional elements like a myth).
• Option c: "Detail" is a small part, not related.
• Option d: "Description" is about telling what something is like, not a synonym for myth.

1. Question 4:

• "Astronomer" studies celestial bodies. "Astro -" is related to stars (e.g., "astrophysics" - study of stars and other celestial objects).
• Option a: "Apple" has no relation.
• Option b: "Man" (like in "anthropo -") is for humans.
• Option d: "Moon" is a specific celestial body, but "astro -" is more general (stars).

1. Question 5:

• Option a: There is gravity on the Moon (about 1/6 of Earth's).
• Option b: Newton described gravity (laws of gravitation), didn't invent it.
• Option c: Heavier objects have more gravity (as \(F = mg\), \(g\) is constant near Earth's surface, \(m\) is mass).
• Option d: Gravity pulls matter towards a center, making planets spherical (as it minimizes potential energy).

Answer:

1. C. by observing the shadow of the Earth on the Moon during an eclipse
2. B. The pencil will hit the ground first because the leaf is slowed down by air resistance.
3. B. legend
4. C. stars
5. D. Gravity is what causes planets to be spherical.