Lab Extension Post-Lab
 s
Since the graph is linear and
contains (0,0)
 cm
v

v t
Velocity vs. Time
cm 

   s 
v  # 
 s 


t s 
Lab Extension Post-Lab
 s
Since the graph is linear and
contains (0,0)
 cm
v

v t
Velocity vs. Time
t
cm 

 

s
v #

s 



v
What does the slope of

your v vs. t graph mean?
The cart' s velocity increased
t s 
# cm
s
every second.
Lab Extension Post-Lab
 s
 cm
v
Velocity vs. Time

Accelerati on a  - the slope of a

graph of v vs. t
t
- the rate of change
of velocity

 v
a
t

v
t s 
Lab Extension Post-Lab
 s
 cm
v

v t
cm 

 
s
v #

s 


Velocity vs. Time
t

v
Units :
cm
cm
cm
cm 11 cm
cm
s  cm
 ss   
2
s
s
ss ss
s
t s 
Lab Extension Post-Lab
 s
 cm
v

v t
Velocity vs. Time
  cm
v   # cm 22t t

ss 
t

v
The y - intercept is negligible, meaning

that when the t  0 s, the v  0 cm .
s
t s 
 s
 m
v
Lab Extension Post-Lab
What would change on the graph if you
started the cart several centimeters
BEFORE the 0 cm mark so that the disk is
moving when recording begins?
Velocity vs. Time
Start at 25 cm
then 0 cm

vo
t s 

Initial Velocity vo  - The y - intercept of a graph
of velocity vs. time.
 s
 m
v
Lab Extension Post-Lab
  
v  at  vo
Final Velocity
  
v  vo  at

vo
One Dimensional, Uniformly
(Constant) Accelerated Motion
t s 
Lab Extension Post-Lab

Compare the slope of the x vs. t 2 graph from the original Lab with

the slope of the v vs. t graph from the Lab Extension.

Slope of the x vs. t 2 graph

Slope of the v vs. t graph
from the original Lab
from the Lab Extension
1
 1 
Accelerat ion  a 
2
 2 
Acceleration
Fill in the blank for the meaning of
the slope in the original Lab.
When writing the original lab report,
simply state that the slope is onehalf the acceleration.
Proof

v
 

v  at only when vo  0

Area under the curve  x

v
t
t
1
Area  bh
2
 1 
xx  tv

2
  1 
x  xo  t (at )
2
 1 2

x  at only when vo  0
2
Proof

x  #

xcm position vs. time
y  m

xcm
t s 
position vs. time
1

x  a
2
2
t
2
x  b
t
2
 

If you graph displacement x  vs. time squared t 2
2
 
t s
2
the slope must be
1 
one - half the accelerati on  a !!!!
2 