2. 1 ~ Through the Looking-Glass by Lewis Carroll

3. 2 Linear Motion of a Segment translation of the body such that its orientation in space does not change

4. 3 single Linear Motion - monitor a single point or a series of points (e.g., body’s center of mass while airborne, the head in running) the point about which the mass of the object is BALANCED it represents the point where the TOTAL effect of GRAVITY (weight) acts on the object

5. 4 Angular Motion body rotates around a fixed axis rotation

6. 5

7. 6 Leg Swing during gait (walking/running) AXIS AXIS PASSES THROUGH JOINT CENTER AXIS

8. 7 General Motion combines both linear and angular motion

9. 8 quantities which possesses magnitude but has no direction associated with it Scalars Density Volume Mass

10. 9 the quantity of matter composing a body units = kg (metric) or slug (English) Mass

11. 10 Density mass per unit volume captures effect of size and mass  (“rho”) = m/V units = kg/m 3

12. 11 Volume amount of three-dimensional space occupied by a body for a box - the 3 dimensions are height, width, and depth V box = h*w*d units = m*m*m = m 3 also measured in liters (l): 1 liter = 1000 cm 3

13. 12 VECTORS have both magnitude and direction This can be shown pictorially by using an arrow. length of arrow = magnitude of force direction arrow points = direction of force kinematics acceleration velocity displacement kineticsForceTorque

14. 13 Force (F) force - a push or pull acting on a body F = ma magnitude (size) direction (line of action) point of application BOX F pt of application line of action SI Units (“newtons,” N) 1 N = (1 kg) (1 m/s 2 ) English units (lb) 1 lb = (1 slug) (1 ft/s 2 )

15. 14 Forces are best described by VECTORS because a vector describes both the SIZE (magnitude) and DIRECTION of the force.

16. 15 Weight amount of gravitational force exerted on a body W = mg (g = -9.8 m/s 2 on earth) CM W

17. 16 Pressure amount of force per unit area P = F/A units = N/m 2 = Pa (Pascal) high heel example (p. 67)

18. 17 Torque (T) aka “Moment of Force” angular analog of Force causes rotation T = Fd units = N m AXIS OF ROTATION Moment Arm

19. 18 NOTE: d is the perpendicular distance between a force’s line of action and a parallel line passing through the axis of rotation Axis of Rotation line of action parallel line moment arm d is known as a “moment arm” Why is a door knob on the outer edge of a door?