#### Transcript research of air resistance Oida Nakamura

```Koshi High School
Oida Ryosuke
Nakamura Kazuki
Air resistance affects falling objects
 When we can’t ignore air resistance, the
faster the speed of a falling object, the
higher the air resistance
 When air resistance becomes equal to
gravity, the object reaches terminal
velocity
 We want to research the relationship of
terminal velocity and air resistance

To research the relationship of terminal
velocity and air resistance when an
aluminum cup falls in the air
 Why choose an aluminum cup?
→Observation is easy
Reaches terminal velocity
immediately

First only gravity affects the
object
When the object gains speed,
it’s affected by air resistance
At low speeds:
R=kv
R …air resistance
v …terminal velocity
k …constant
When the object reaches
a fixed speed, air
resistance and gravity
are balanced
and the aluminum cup
falls at a constant speed
This is called Terminal
velocity
Air resistance force involves three things:
①Air resistance coefficient
②Surface area
③Speed
For example
Flat board
1.2
Glove
0.5
Prius 0.26
resistance has viscous resistance and
inertial resistance.
viscous resistance・・・proportional
to the speed
inertial resistance・・・proportional to
the square of the speed
Ｒ＝kv
Ｒ＝kv２
Ｒ is air resistance (in N)
v is speed (in m/s)
k is a constant of proportionality
We pile aluminum cups and increase
the amount of mass.
We look for changing resistance from
changing terminal velocity and we
search for the relationship 質量が増えた
ときの終端速度の変化から、抵抗力の変化を





We recorded the aluminum cups falling along
the experimental device.
The experimental device・・・it is a ruler attached
to a board（メジャーを板に垂直に設置したもの）
We checked the video on a PC and we replayed
each frame. We searched for the distance.アルミ
カップが決められたフレーム数で進む距離を求めた。
Then we searched for how much the distance
changed each second. 求めた距離を一秒間に進む


Next, we piled aluminum cups and we
did a similar experiment (figure1)
Figure １ piled aluminum cups
the number of
aluminum cups
Square of the
terminal velocity
（m/s）２
Terminal velocity
（m/s）
1
2.24
5.02
2
2.84
8.07
3
4.13
17.06
4
4.86
23.62
5
6.19
38.32
6
7.01
49.14
Figure ２ （the results of experiment 2）
We expected「R=kv2」
→When we reduced the
number of aluminum cups,
we got good data.
 When we increased the
number of aluminum cups
→The results are
markedly different
because the coefficient of
air resistance changed

Don’t change the shape of the object to
be dropped
 By increasing the mass, find the change
in resistance from the change in
terminal velocity, and examine the
relationship



The increased mass of the aluminum cup
with reference to FIG. 3
We found the terminal velocity in the same
manner as Experiment 1
Figure 3 The folded aluminum cup that
was placed
the number of
aluminum cups
Terminal velocity
（m/s）
Square of the terminal
velocity（m/s）２
1
2.24
5.02
2
2.84
8.07
3
4.13
17.06
4
4.86
23.62
5
6.19
38.32
6
7.01
49.14
7
6.04
36.48
8
6.38
40.70
9
6.53
42.64
When we increased
the number of cups,
the graph was
disturbed
→Aluminum cups
didn’t reach
terminal velocity
 The relationship was
proportional to the
square of the mass
and speed


When aluminum cups are falling, air
resistance force is proportional to the
square of the speed.
We will change the conditions of the
falling aluminum cup.
 We will investigate the relationship
between the speed and resistance of
falling aluminum cups

Thank you for listening!
```