As we begin our class today,
Dear Lord, send your spirit of
wisdom to be with me,
so that the knowledge that
will be imparted to me will not
put to waste.
AMEN.
Acceleration
LEARNING TARGET:

Define acceleration;

Distinguish between acceleration and deceleration;

Explain the different ways of acceleration; and

Describe the acceleration of objects through problem
solving.
 Define acceleration.
Acceleration

Acceleration – change in velocity over
time.

a = ΔV/t = Final velocity – Initial Velocity
Time
Acceleration is a “rate”
 Units m/s2

 Distinguish between acceleration and deceleration.
Acceleration
When an object is increasing in velocity
over time it is said to be accelerating.
(positive acceleration)
 When an object is decreasing in velocity
over time it is said to be decelerating.
(negative acceleration)
 If an object is moving at constant velocity
it is said to be moving with zero
acceleration

 Explain the different ways of acceleration.
Three Ways to “Accelerate”

Speed Up

Slow Down

Change Direction
Describe the acceleration of objects through problem solving..
Positive Acceleration
1.
An Indy-500 car’s velocity increases from 4.0
m/s to 36 m/s over a 4.0 second period. What
is the acceleration?
GIVEN:
v final = 36 m/s
v initial = 4.0 m/s
t = 4.0 second
FIND:
a=?
FORMULA:
a = v final – v initial / t
SOLUTION AND ANSWER:
a = 36 m/s – 4.0 m/s = 32m/s =
4.0 s
4.0 s
8.0 m/s²
Negative Acceleration/
Deceleration
The same car slows from 36 m/s to 15 m/s over 3
seconds. What is its average acceleration over this
time interval?
GIVEN:
v final = 15 m/s
v initial = 36 m/s
t = 3 seconds
FIND:
a=?
FORMULA:
a = v final – v initial / t
SOLUTION AND ANSWER:
a = 15 m/s – 36 m/s = -21m/s = -7 m/s²
3.0 s - 0 s
3.0 s
“decelerating”
2.
Time
3. A car accelerates at a rate of 1.5 m/s2. If its
original speed is 4.0 m/s, how many seconds will it
take the car to reach a final speed of 12.0 m/s?
GIVEN:
a = 1.5 m/s2
v initial = 4.0 m/s
v final = 12.0 m/s
FIND:
t=?
FORMULA:
t = v final – v initial / a
SOLUTION AND ANSWER:
t = 12 m/s – 4.0 m/s = 8 m/s____ = 5.33 s
1.5 m/s²
1.5 m/s²
V final
4. A cart rolling down an incline for 2.5 seconds has
an acceleration of 2.0 m/s2. If the cart has a
beginning speed of 1.0 m/s, what is its final speed?
GIVEN:
a = 2.0 m/s2
v initial = 1.0 m/s
t = 2.5 s
FIND:
V final = ?
FORMULA:
v final = v initial + (a x t)
SOLUTION AND ANSWER:
v final = 1.0 m/s + ( 2.0 m/s² x 2.5 s )
= 1.0 m/s + ( 5 )
= 6 m/s