This document defines velocity, acceleration, and how to calculate acceleration. It states that velocity is the rate of change of distance over time, while acceleration is the rate of change of velocity over time. Positive acceleration means speeding up, and negative acceleration means slowing down. The document provides the formula for calculating acceleration as the change in velocity divided by the change in time. It then works through examples of calculating the acceleration of a car, roller coaster, and jet fighter to demonstrate how to apply the formula.

1. What is Velocity (Speed)?
• Velocity (speed) – the rate of change of distance
per unit of time.
Speed =
d2 – d1
t2 – t 1
Velocity =
d2 – d1
t2 – t 1

2. What is Acceleration?
• If velocity is the rate of change of distance per
unit of time, then acceleration is …
• … the rate of change of velocity per unit time.

3. What is Acceleration?
• Positive acceleration = speeding up
• Negative acceleration = slowing down
(decelerate)

4. Calculating Acceleration
Velocity =
d2 – d1
t2 – t 1
Acceleration=
v2 – v1
t2 – t1
• So, to determine acceleration, you must know the
beginning velocity, the final velocity, the
beginning time, and the final time.
• Again, this is just like slope on a graph!

5. Calculating Acceleration

6. Calculating Acceleration
• What is the acceleration car that goes from 0 ft/s
to 200 ft/sec in 5 seconds?
• Beginning velocity (v1) = 0 ft/s, final velocity (v2)
= 200 ft/s, beginning time (t1) = 0 seconds, and
final time (t2) = 5 seconds, so

7. Calculating Acceleration
Acceleration =
v2 – v1
t2 – t 1
200 ft/s – 0 ft/s
Acceleration =
5s–0s
• Which equals 200 ft/s ÷ 5 s, or
• 40 ft/s2 (or 40 feet per second per second)

8. Calculating Acceleration
• What is the acceleration roller coaster that
goes from 5 m/sec to 0 m/sec in 10 seconds?
• v1 = 5 m/sec, v2 = 0 m/sec, t1 = 0 seconds, and t2
=10 seconds, so

9. Calculating Acceleration
Acceleration =
Acceleration =
v2 – v1
t2 – t 1
0 m/s – 5 m/s
10 s – 0 s
• Which equals: – 0.5 m/s2
• Acceleration is negative, so roller coaster is
slowing down.

10. Calculating Acceleration

11. Calculating Acceleration
• What is the acceleration of a jet fighter that goes
from 0 mph to 165 mph in 2 seconds?
• v1 = 0 miles/hr, v2 = 165 miles/hr, t1 = 0 seconds,
and t2 = 2 seconds

12. Calculating Acceleration
• First, you must make the time units all the same.
• Initial Velocity = 0 miles/hour = 0 miles/second
• Now, convert 165 miles/hr to miles/sec

13. Calculating Speed and Velocity
165 miles
hr
x
1 hr
3,600 sec
• Now, calculate acceleration
=
0.046 miles
sec

14. Calculating Acceleration
0.046 miles/s – 0 miles/s
Acceleration =
2s–0s
• Which equals 0.023 miles/s2 , or
• 121 ft/s2 (or almost 4 g’s)

15. Brain Pop Clip
• BrainPOP on Acceleration