PHYSICS 103: Lecture 2

1. PHYSICS 103: Lecture 2 Agenda for Today: • Description of Motion • Speed, Velocity • Acceleration • Graphing Motion • Motion under uniform acceleration

2. Description of Motion Speed and Velocity How fast is an object moving? Instantaneous speed = rate at which distance is covered at any given instant How do we describe the direction of motion? Velocity Vector: magnitude (speed) and direction

3. Description of Motion Acceleration Instantaneous acceleration = rate at which velocity is changing at any given instant

4. Graphing Motion Distance Velocity time time What would acceleration vs. time look like?

5. i)  Gets in her car and goes 30 mph for 5 minutes to the nearest stop sign • ii) She realizes she forgets something, makes an immediate U turn and goes 30 mph in the opposite direction (back home) for 5 minutes • iii) She searches for her textbook for 10 minutes in her house • iv) She then speeds at a constant speed of 100 mph for half an hour to make in time for class.

6. v= vo + at acceleration Final velocity Initial velocity: velocity at t = 0 d = d0 + v0t + 1/2at2 Initial height: height at t = 0 acceleration Initial velocity: velocity at t = 0 Motion with Uniform Acceleration When an object accelerates at a constant rate the following applies:

7. Main Points from Today’s Lecture • Description of Motion Average Instantaneous • speed - Average Instantaneous • velocity - Average Instantaneous • acceleration - • Graphing Motion • Motion with Uniform Acceleration

8. HW Read Ch 3 Ch 2: Q8, Q10, Q11, Q16, E1, E5, E10, E11,E12