Name: _______________________
Acceleration Post Lab: Part I
Look at your data from 2 objects to answer the following questions.
1.
Did the acceleration of object 1 remain constant throughout the fall? How do you know?
2. Did the acceleration of object 2 remain constant throughout the fall? How do you know?
3. Does the mass of an object affect acceleration? How do you know?
Read the following passage:
The acceleration of a free-falling object (on earth) is 9.8 m/s/s. This value (known as the acceleration of
gravity) is the same for all free-falling objects regardless of how long they have been falling, or whether they
were initially dropped from rest or thrown up into the air.
Yet the questions are often asked "doesn't a more massive object accelerate at a greater rate than a less massive
object?" "Wouldn't an elephant free-fall faster than a mouse?" This question is a reasonable inquiry that is
probably based in part upon personal observations made of falling objects in the physical world. After all,
nearly everyone has observed the difference in the rate of fall of a single piece of paper (or similar object) and
a textbook. The two objects clearly travel to the ground at different rates - with the more massive book falling
faster.
The answer to the question (doesn't a more massive object accelerate at a greater rate than a less massive
object?) is absolutely not! That is, absolutely not if we are considering the specific type of falling motion known
as free-fall. Free-fall is the motion of objects that move under the sole influence of gravity; free-falling objects
do not encounter air resistance. More massive objects will only fall faster if there is an appreciable amount of
air resistance present.
Follow Up Questions.
1) What is the acceleration due to gravity (a number) for ALL objects in a free fall?
2) Should the mass of an object affect acceleration?
3) State the relationship between the mass of an object and acceleration.
4) Did your data support the above answers? If not, what would account for the differences?
5) If you drop a tennis ball and a car from the top of the empire state building…which would hit the ground
first?
Use the following data from the 2 objects to calculate acceleration.
Object: Beach Ball
A
Total
Distance
(meters)
B
Times
C
Δ Time
During
Interval
D
Instantaneous
Velocity @
each time
(m/s)
E
Δ Velocity
During
Interval
F
Instantaneous
Acceleration
@ each time
(m/s2)
d=0
4.9
19.6
t=0
1
2
9.8
19.6
0
0
0
44.1
3
29.4
D
Instantaneous
Velocity @
each time
(m/s)
E
Δ Velocity
During
Interval
F
Instantaneous
Acceleration
@ each time
(m/s2)
0
0
0
Object: Jet Plane
A
Total
Distance
(meters)
B
Times
C
Δ Time
During
Interval
d=0
44.1
78.4
t=0
3
4
29.4
39.2
122.5
5
49.0
Question: In “real life”, why might you not get these results?