1. Newton’s Law of Universal Gravitation
Gravity acts between all objects in the universe.
Gravity between objects depends on two things
Mass – the more mass something has, the greater the force of gravity.
Distance – as distance increases, the force of gravity decreases.

2. Gravity and Acceleration
Initially a falling object has a velocity of 0.0m/s
The object will speed up to 9.8m/s every second
9.8m/s = acceleration of gravity
Symbol = ag

3. So, according to Newton’s law of gravitational force, all objects in the universe exert an attractive force on each other.
If this is true, why don’t we float off toward the Sun, which has a much greater mass than Earth?

4. 1. Which of the following best describes an object’s velocity during freefall under ideal conditions?
An object travels at a constant velocity throughout the fall
An object’s velocity increases as it falls
An object’s velocity decreases as it falls
An object during freefall does not have a measurable velocity

5. 2. Maddie drops a baseball from a window on the tenth floor of her apartment building. Under ideal conditions, what would be the baseball’s velocity after two seconds?
2.0 m/sec c m/sec
9.8 m/sec d m/sec

6. 3. The mass of two objects is an important factor in determining the force of gravity between them. What is the second factor?
their volume c. their diameter
their density d. the distance between them

7. 4. What is the best explanation for why the moon orbits Earth rather than Earth orbiting the moon?
Earth has less mass than the moon
Earth rotates faster than the moon rotates
The moon has no gravitational pull on anything
Earth has more mass than the moon

8. 5. Suppose you roll a basketball and a baseball toward each other
5. Suppose you roll a basketball and a baseball toward each other. How does this affect the force of gravity they exert on one another?
a. It increases c. It stays the same
b. It decreases d. It disappears

9. Page 111 Notebook
Write 5 Facts about Gravity in your notebook. 1) 2) 3) 4) 5)