Galileo, Newton and the Falling Apple: teacher key

Gravity, grade 3 edition, written for 3rd grade. Learn what Galileo and Isaac Newton found out about gravity, from falling objects to the Moon and the planets.

Read the book. Print this page for the key.

Questions and answers

1. What did Galileo show about falling things?
   • Light ones fall faster
   • They speed up at the same rate with no air (answer)
   • Nothing falls
2. What is said to have inspired Newton?
   • A kite
   • A falling apple (answer)
   • A boat
3. When was Newton's theory of universal gravitation published?
   • 1687 (answer)
   • 1587
   • 1787
4. What is the main cause of ocean tides?
   • The wind
   • The Sun's heat
   • The Moon's pull (answer)
5. What keeps Earth moving around the Sun?
   • The Sun's gravity (answer)
   • The wind
   • The Moon

Words

• gravity: a pulling force
• mass: amount of stuff
• ellipses: oval paths
• tides: sea rising, falling