Topic 7 Lesson 1 and 2 Combo

Eva goes to the mechanic with her mother to fix their car’s tires. She watches as the tires spin on a central pole. This reminds her of how Earth spins on an imaginary line that passes from the North Pole to the South Pole. This line is called Earth's ​ (a)   The motion of Earth spinning around this imaginary line is called Earth's ​ (b)   .​

Mr. Lee used a globe to demonstrate to his class that Earth rotates around a central line. He also demonstrated that Earth travels around the sun by picking up the globe and walking in a circle around his desk. It takes Earth one year to make one trip around the sun. What word is used to describe one object moving around another object?

Karina is conducting an experiment based on Isaac Newton's law of universal gravitation. She is testing the strength of the force of gravity between two objects. What factors determine the strength of the force of gravity? Choose the two that apply.

Kevin is taking a meteorology class in which he studies weather and climate. He learns that Earth's position relative to the sun determines the seasons. For example, more sun shines on the Northern Hemisphere in July than in December.

Why does the sun shine more directly on Earth’s Northern Hemisphere during the summer months?

The ​ (a)   occurs twice each year. It is the day when the sun appears at either its highest or lowest point in the sky. The ​ (b)   also occurs twice each year. It is the day when the sun passes directly overhead at noon if you are standing at the equator. During these occurrences, night and day are both 12 hours long.

Rachel reads about how astronauts appear to be weightless in space. She wonders how Earth stays in orbit around the sun when astronauts float while in orbit around Earth. She remembers that there is a force that keeps Earth in orbit around the sun. This force is the same force that keeps astronauts in orbit around the Earth. It also helps to explain why they appear to be weightless. What is this force?