1. Physics Lab 2 Graphical Analysis of Motion Eleanor Roosevelt High School Chin-Sung Lin

2. Average / Instantaneous Speed & Velocity

3. Speed A speed (v) is a scalar quantity Distance (d) covered per unit of time (t). Speed is a measure of how fast something is moving. It is the rate at which distance is covered v = d / t Unit: meters per second (m/s), miles per hour (mi/h), kilometers per hour (km/h)

4. Velocity A velocity (v) is a vector quantity Velocity is the measurement of the rate and direction of change in the displacement (d) of an object v = d / t The speed is the magnitude of velocity Unit: meters per second (m/s), miles per hour (mi/h), kilometers per hour (km/h)

5. Speed Speed: the slope of the distance-time (d-t) graph t d slope = v (speed)

6. Speed Velocity: the slope of the displacement-time (d-t) graph t d slope = v (velocity)

7. Constant Speed/Velocity The speed/velocity at any instance of an object is constant t d slope = v t v slope = 0 v

8. Average Speed Average speed (v): v = d / t d = total distance covered (m) t = time interval (s) t d slope = v

9. Average Velocity Average velocity (v): v = d / t d = total displacement (m) t = time interval (s) t d slope = v

10. Instantaneous Speed The speed (v) at any instance of an object is called the instantaneous speed It is equal to the slope of the tangent line at that moment t d slope = v

11. Instantaneous Velocity The velocity (v) at any instance of an object is called the instantaneous velocity It is equal to the slope of the tangent line at that moment t d slope = v

12. Acceleration

13. An acceleration (a) is a vector quantity acceleration is the rate of change of velocity with time a = Δv / t a = acceleration (m/s 2 )  v = change of velocity (m/s) t = time interval (s)

14. Acceleration An acceleration (a) is also a scalar quantity When linear (straight-line) motion is considered, it is common to use speed and velocity interchangeably and the acceleration may be expressed as the rate at which speed changes a = Δv / t a = acceleration (m/s 2 )  v = change of speed (m/s) t = time interval (s)

15. Acceleration Acceleration: the slope of the speed/velocity-time (v-t) graph t v slope = a (acceleration)

16. Constant Acceleration The acceleration at any instance of an object is constant In high school physics, we only deal with constant acceleration t v slope = a t a slope = 0 a

17. d-t, v-t & a-t Graphs

18. Distance, Speed & Acceleration d-t t v slope = a x t a slope = 0 axax t d slope = increasing at constant rate v-t a-t

19. Displacement, Velocity & Acceleration due to Gravity d-t t v slope = g t a slope = 0 g t d slope increasing at constant rate v-t a-t dydy Slope of v-t Area under v-t

20. The End