9 5 Force Diagrams Focus Assignment A car

9. 5 Force Diagrams Focus Assignment: A car with an automatic transmission is in drive. 1) The driver has his foot on the brake. 2)The driver then releases his foot off the brake. Sketch the two scenarios using arrows that represent the different forces present.

3. Free Body Diagram Picture representation used to show forces acting on an object

4. Force of Gravity (Fgrav) a. k. a. weight. It’s equal to the mass times the acceleration due to gravity w = mg Fgrav = mg

5. Normal Force (Fnorm) opposes force of gravity; always acts perpendicular to the surface Fnorm

6. Force Applied (Fapp) a push or pull on an object other than gravity Fapp

7. Force of Friction (Ffric) Ffric opposite to the motion of the applied force, always parallel to the surface Fapp This shows STATIC FRICTION. Both arrows are equal AND opposite, canceling each other out resulting in

7. Force of Friction (Ffric) Ffric opposite to the motion of the applied force, always parallel to the surface Fapp This shows KINETIC FRICTION. The arrows are NOT equal. This results in an acceleration (a. k. a. UNbalanced

Putting It All Together: Static Friction Force Diagram Fnorm Ffric Fapp Fgrav = mg

Putting It All Together: Kinetic Friction Force Diagram Fnorm Ffric Fapp Fgrav = mg

Scenario 1: A car at a red light Fnormal Fgravity

Scenario 2: A car speeding up Fnormal FFric, Air Fapplied Fgravity

Scenario 3: A car traveling at constant speed Fnormal FFric, Air Fapplied Fgravity

Scenario 3: A car slowing down Fnormal FFric, Air Fapplied Fgravity