February 10, 2012 Physics Mr. Payne

Multiple Choice Answers Number Answer 1 B 4 A 7 D 2 C 5 8 3 6 9

Short Answer Question 10 Discuss the following statement: “A satellite is continually in free fall.” Answer A satellite in a circular orbit around Earth moves like a projectile. One component of its motion is parallel to Earth’s surface, while the other component is a free-fall acceleration toward Earth. The horizontal component of the motion is just the right magnitude for Earth’s curved surface to fall away at the same rate as the satellite’s free-fall acceleration.

Earth exerts a 1.0 N gravitational force on an apple. Short Answer Question 11 Earth exerts a 1.0 N gravitational force on an apple. Does the apple accelerate toward Earth, or does Earth accelerate toward the apple? Explain your answer. Answer They both accelerate toward each other. Earth’s acceleration is extremely small compared to that of the apple because Earth has a much greater mass than the apple does.

Short Answer Questions 12 and 13 Earth exerts a 1.0 N gravitational force on an apple. What is the magnitude of the gravitational force the apple exerts on Earth? Answer: 1.0 N What is Earth’s weight in the apple’s gravitational field?

Short answer questions 14 and 15 Briefly, how did Ptolemy describe the motion of the planets? ANSWER: Ptolemy described the planets moving in small circles called epicycles while simultaneously moving in larger circles around Earth. Briefly, how did Copernicus describe the motion of the planets? Copernicus described the planets, including Earth, moving in circular orbits around the sun.

Short Answer question 16 According to the big bang theory, what occurred in the brief instant after the big bang? ANSWER: The four fundamental interactions of physics operated in a unified manner. The high temperatures and energy caused all particles and energy to be indistinguishable.

PROBLEMS PROBLEM ANSWER 17 4.10 X 105 m = 410 km 18 9.5 X 103 kg 19 1.4 X 105 m/s 20 5.4 X 106 s

Big bang theory Review pages 936-942 from the textbook. Be able to describe in general terms the history and possible fates of the Universe. Know the four fundamental forces, and when they separated from their common beginning.