1. Lecture on Gravity, Inertia and Friction

2. Balanced or unbalanced?
Gravity Inertia Friction
Balanced or unbalanced?
Action
Reaction

3. Gravity balanced UN BALL Speed (m/s) Ground Time (mSec)

4. Inertia balanced UN PUTTER Speed (m/s) BALL Time (mSec)

5. Friction balanced UN SKATE Speed (m/s) Time (Sec)

6. A car is traveling down a hill
A car is traveling down a hill. Which of the following will affect the amount of energy the car has?
how long the car is
the time of day
how much the car weighs
the color of the car

7. causes physical deformation generates heat
Friction  
the resistive force that occurs when two surfaces travel past each other.
causes physical deformation
generates heat

8. the resistive force that occurs when two surfaces contact each other.
Friction  
the resistive force that occurs when two surfaces contact each other.  

9. Oliver the dog doesn't want to walk in the rain
Oliver the dog doesn't want to walk in the rain. He can make his owner pull harder on the leash to get him out the door by sitting on the vinyl floor. sitting on the tile floor. sitting on the carpeted floor. sitting on the wood floor.

10. Pauline needs to measure the sliding friction of a brick
Pauline needs to measure the sliding friction of a brick. How should she go about doing this?
attach the brick to a string and then to a spring scale and read the force needed to quickly lift the brick off the ground
drag the brick by a string attached to a spring scale so that it gradually speeds up
drag the brick by a string attached to a spring scale along the surface of a table at a constant speed and read the force
hang the brick from a string attached to a spring scale and read the force

11. Sliding friction-the drag force created when the surface of one object slides across the surface of another object.
Sliding Friction Lab
Object
Surface
force (Newstons)

12. terminal velocity gravity will accelerate an object until air resistance (friction) does not allow it to go any faster.
gravity
air resistance

13. the ball with a mass of 75 kg the ball with a mass of 25 kg
In the absence of air resistance, which of these objects will fall at the fastest rate when dropped?
the ball with a mass of 75 kg
the ball with a mass of 25 kg
the ball with a mass of 10 kg
They all fall at the same rate.

14. Pressure is the amount of force exerted over a certain area.
Pressure = Force
Area

15. Pressure = Force (newtons)
Area (m2)
1 Pascal = 1 Newton/meter2

16. Work

17. {
Work
Distance
W = f • d
Force {
Distance