1. Force, Friction, & Gravity Study Guide
Chapter 10 Section 1 & 2
Force, Friction, & Gravity Study Guide

2. What is the difference between mass & weight?
Mass – amount of matter in an object
Measured in kg
Weight – how much gravity is pulling an object
Measured in N

3. What is the difference between Mass and Weight?

4. How will your weight change if you were to travel to a more massive planet than Earth?
Earth has a gravity, which is based on the mass of Earth.
A more massive planet than Earth would have a stronger gravitational pull
You would weigh more on a planet more massive than Earth.

5. What is the SI unit for force?
Force is represented Newtons (N).

6. Why is it possible to throw a baseball much further than a bowling ball?
The baseball has a lighter mass than the bowling ball.
The less mass, the less gravitational pull, the easier force it accelerate that object.
The greater mass, the greater gravitational pull, the hard force need to accelerate the object.

7. How would the mass of an object be different if it were on the moon instead of Earth.
Mass = how much matter is in an object
The mass of an object cannot change, regardless of whether its on Earth or on the moon.

8. In air, a leaf will fall more slowly than a baseball. Why?
The baseball has less surface area and experiences less air resistance.
The leaf has more surface area and experiences more air resistance.

9. How would the speeds of the falling leaf and baseball change if there was no air?
No air = no air resistance
No air resistance = no upward force slowing down the leaf
No air = lead and baseball both fall the ground with the same speed at the same time.

10. Why do objects on Earth’s surface tend to fall at different rates?
All objects are supposed to fall at the same rate, but this doesn’t always happen
Air Resistance = upward force exerted on falling objects; type of fluid friction
Falling objects with greater surface area experience more air resistance

11. What are two factors that affect gravitational attraction of objects?
Two factors affect gravitational attraction: Mass & Distance
Greater mass = greater gravitational force
Closer the objects = greater gravitational force

12. What is the acceleration due to gravity on Earth?
An object that falls to the ground accelerates.
The acceleration of an object to Earth is 9.8 m/s/s

13. What is the relationship between mass and gravitational force?
Greater mass = greater gravitational force

14. What are two factors that determine the strength of friction?
Strength of friction depends on:
How hard the surfaces push together
Types of surfaces involved

15. What is the fluid friction that is exerted on all falling objects?
Air resistance

16. How do you represent force on paper?
Represented with an arrow ( or )
Arrow points in direction of the force

17. What are the four types of friction? Give an example of each.
Static Friction
Sliding Friction
Rolling Friction
Fluid Friction

18. What is a force?
A push or a pull on an object

19. When the only force on a falling object is gravity, the object is said to be in _______?
On earth, gravity is a downward force affecting all objects
Free Fall
When only force acting on a falling object is gravity

20. What is the force that is exerted when two surfaces rub against each other?
Friction
The force that two surfaces exert on each other when they rub against each other

21. What is the force that is exerted when objects are pulled towards each other?
Gravity
A force that pulls objects toward each other

22. Who is the scientist that discovered gravity?
Isaac Newton said, gravity is a force acts to pull objects straight down toward Earth’s center

23. Which surfaces provide the least amount of friction, smooth or rough?
Smooth surfaces provide less friction than rough surfaces

24. How do you describe force?
Described by strength and direction
Strength is measured in NEWTONS (N)
Direction represented with an arrow ()

25. Objects with the greatest _______ experience more air resistance?
Greater surface area= greater air resistance
Ex: paper ball versus sheet of paper

26. Forces with the same strength that cancel each other out are called?
Balanced forces

27. Forces acting on an object that result in a net force and a change in motion are called?
Unbalanced forces