Q: Why do satellites and spacecraft launched from Earth need to reach a specific speed to escape Earth's surface?
A: to overcome Earth's gravitational force

Q: One 7.0 kg bowling ball is lifted to a storage shelf 1.0 m above the floor. A second 7.0 kg ball is lifted to a storage shelf 2.0 m above the floor. Which of the following best explains why the measured force of gravity on each ball is nearly identical?
A: The distance of each ball from Earth's center of mass is almost identical.

Q: A layer of solid brittle rock comprises the outer 100 kilometers of Earth. This layer, which contains both the crust and the upper mantle, is called the
A: lithosphere.

Q: In your body, what two organs work together to make sure that oxygen gets to all the other organs of your body?
A:
Heart and lungs