Recall:

1. Displacement: Dx = x_f - x_i
2. Average velocity: v_avg = Dx / Dt
3. Instantaneous velocity: the average velocity in the limit the time interval goes to zero, also the slope on the position versus time graph.
4. Average acceleration: a_avg = Dv / Dt = (v_f-v_i)/(t_f-t_i). Note that v_f and v_i are instantaneous velocities.

Example: P2.16

A car is travelling initially at +7.0m/s. It accelerates at a rate of +0.80m/s² for 2.0s. What is the final velocity?

1. Read the problem.
2. Make a sketch.
3. Identify the data: v_i = 7.0m/s, a = 0.80m/s², Dt = 2.0s.
4. We will use the equation a = (v_f - v_i) / Dt
5. Rewrite the equation to solve for v_f = v_i + aDt = 7.0m/s + (0.80m/s²)(2.0s) = 8.6m/s
6. Check the answer.

Motion Diagram

1-D Motion with Constant Acceleration

Free Fall

Chapter 3: Vectors and 2-D Motion

Vectors and Scalars

Some Properties of Vectors

Components of a Vector