1. AP Phys B Test Review Kinematics and Newton’s Laws 4/28/2008

2. Overview Units and Dimensions Units and Dimensions Scalars and Vectors Scalars and Vectors –1-D, 2-D, and 3-D Particle Kinematics Particle Kinematics Newton’s Laws of Motion Newton’s Laws of Motion –Gravity –Friction

3. Units and Dimensions Metric System Metric System Conversions Conversions Dimensional Analysis Dimensional Analysis Order of Magnitude Estimations Order of Magnitude Estimations

4. Scalars and Vectors Scalars: Magnitude only. Scalars: Magnitude only. Vectors: Magnitude and direction. Vectors: Magnitude and direction. –Vectors components Cartesian coordinates Cartesian coordinates Trigonometry Trigonometry –Find the magnitude of a vector  v vxvx vyvy

5. Scalars and Vectors Vector Addition and Subtraction Vector Addition and Subtraction –Graphical Representation “Head to tail” –Mathematical operation Vector multiplication Vector multiplication –Dot Product –Cross Product

6. Particle Kinematics Distance and Displacement Distance and Displacement –Distance: length –Displacement: length and direction Speed and Velocity Speed and Velocity –Speed: distance/time –Velocity: displacement/time Acceleration Acceleration –Change in speed (velocity)/time

7. Particle Kinematics Graphs Graphs –Distance vs. time graphs; slope –Velocity vs. time graphs; slope, area Instantaneous vs. average values Instantaneous vs. average values

8. Particle Kinematics Problem Solving Strategies Problem Solving Strategies –Identify known quantities –Key words: at rest, constant speed Free fall problems Free fall problems –Acceleration due to gravity: 9.8 m/s 2 Use common sense! Use common sense!

9. Particle Kinematics Equations of Motion Equations of Motion VfViatdVfViatd x y

10. Newton’s Laws 1 st law (Law of Inertia): An object at rest stays at rest, and object in motion stays in motion in a straight line at a constant speed until acted on by an outside force. 1 st law (Law of Inertia): An object at rest stays at rest, and object in motion stays in motion in a straight line at a constant speed until acted on by an outside force. –Inertia: Resistance of an object to change –Meaning: Things don’t speed up or slow down without a reason.

11. Newton’s Laws 2 nd Law: The acceleration of an object is proportional to the force on that object and is inversely proportional to the mass of the object. 2 nd Law: The acceleration of an object is proportional to the force on that object and is inversely proportional to the mass of the object. –Meaning: The heavier something is, the more force it takes to achieve a certain acceleration.

12. Newton’s Laws 3 rd law: For every action, there is an equal and opposite reaction 3 rd law: For every action, there is an equal and opposite reaction –All forces occur in pairs. –These forces cannot occur on the same object.

13. Newton’s Laws Balanced vs. Unbalanced forces; Equilibrium Balanced vs. Unbalanced forces; Equilibrium Free-Body Diagrams Free-Body Diagrams –Determining acceleration –Normal Force –Tension (pulleys) –Friction (static and kinetic) –Inclined Plane Problems

14. Newton’s Laws Circular Force Circular Force –Radial vs. tangential acceleration –Centripetal force: an unbalanced force Newton’s Law of Universal Gravitation Newton’s Law of Universal Gravitation –Gives the gravitational force between two objects.