1. Unit 2: Acceleration (Lesson 1)
The rate of speeding up or slowing down.

2. Definition: Acceleration = Rate of change of velocity
Formula: vo = initial velocity
v = final velocity
t = time
Example 1: Find the acceleration of a car that slows from 72 km/h to a stop in 3.0 seconds.
10 min

3. Note: Solving the acceleration formula for “v” gives the formula:
Example 2: How long does it take for a commercial jet liner that lands at 200 km/h to come to rest, if it decelerates at 15 m/s2 ?
10 min
Note: Solving the acceleration formula for “v” gives the formula:

4. Brain Break!

5. Find the velocity after 2 seconds. b) When does the ball come to rest?
Your turn! A golfer putts his ball up a hill on a green. The initial velocity is 2.5 m/s and the acceleration is m/s2
Find the velocity after 2 seconds.
b) When does the ball come to rest?
c) Find the velocity after 5.0 seconds.
v = v0 + at
v = 2.5 m/s +(-.75m/s2)(2s)
v = 1 m/s
b) v = v0 + at
0 = 2.5 +(-.75)(t)
0 = 2.5 – .75t
0.75t = 2.5
t = 2.5/.75 = 3.33 seconds
15 min
c) v = vo + at
v = (-.75)(5)
v = m/s (backwards)

6. Practice
#1-2 and 4-5 on pg. 52
#1 and 2 on the Acceleration Problem Set
20 min