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
求め、その関係を調べる。




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
距離に直し、終端速度とした。

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!