1. LESSON Lesson Main Idea 4.2 Acceleration Acceleration occurs when an object speeds up, slows down, or changes direction.

2. LESSON Texas Essential Knowledge And Skills 4.2 Acceleration 8.6(B) Differentiate between speed, velocity, and acceleration. Also covers Process Standards: 8.1(A); 8.2(A), (B), (C), (D), (E); 8.4(A), (B)

3. LESSON Inquiry 4.2 Acceleration Is velocity changing? (p. 162) How does the velocity of this motorcycle racer change as he speeds along the track, enters a curve, leans to the side, and changes direction? On a straightaway, he moves in a straight line. How else can the velocity of the motorcycle change?

4. LESSON Essential Questions 4.2 Acceleration How do speed, velocity, and acceleration differ?

5. LESSON Vocabulary Watch out for these words! 4.2 Acceleration acceleration

6. LESSON A bicyclist rode his bike along a straight path. After 2.0 s, his speed was 2.0 m/s. After 5.0 s, his speed was 8.0 m/s. What was his acceleration during the time 2.0 s to 5.0 s? Solve for Acceleration 4.2 Acceleration

7. LESSON STEP 2 STEP 3 STEP 1 4.2 Acceleration This is what you need to find: acceleration: a This is what you know: initial speed = 2.0 m/s final speed = 8.0 m/s total time = 5.0 s – 2.0 s = 3.0 s Solve for Acceleration, continued

8. LESSON Solve for Acceleration, continued Step 4 4.2 Acceleration

9. LESSON Adrian drops a rock from a cliff. After 4.0 s, the rock is moving at 39.2 m/s. What is the acceleration of the rock? Solve for Acceleration, continued Practice 4.2 Acceleration

10. LESSON 4.2 Acceleration

11. LESSON Essential Question Review 4.2 Acceleration How did what you learned in this lesson help you answer the Essential Question? How do speed, velocity, and acceleration differ?