1. Kinematics Goals: Understand the motion with constant acceleration. Example: Free fall.

2. Q0: Velocity and displacement When the velocity decreases from +5m/s to zero, the displacement is 1)zero; 2)positive; 3) negative; 4) undecided.

3. Identify motions!!

4. Motion at constant acceleration (1D) v av = (v + v 0 )/2 v = v 0 + at x = x 0 + v 0 t + at 2 /2 v 2 = v 2 0 + 2a (x- x 0 )

5. Q1

6. Q2 A driver is driving with + 54 km/hr and sees a yellow light when he is 20m behind the stop lines. Is he able to stop his car before the traffic light if the acceleration he can have is - 5 m/s^2 ? a) yes; b) no.

7. Q3 One car starts accelerating with +5m/s^2 from still (i.e.v=0) when a fast car moving with 10m/s is 10m behind. Is the fast car able to catch the slower one? a)yes; b) no.