Acceleration of the Elevator Box

People tend to call me overweight.

To change the stereotype, I decided to change my weight in a short time.

Realizing that healthy diet and daily excercise takes several month, I searched for quicker way of changing my weight.

Tools: Bodyweight Scale, Elevator

Introduction:

Weight in scientifical definition is a force exerted on an object by gravity.

I decided to see the variation of weight through difference in gravity.

Procedure:

1. Find a nearby elevator.

2. Go to the highest level.

3. Go on the bodyweight scale and measure the actual weight.

4. As the elevator goes down, observe the change of weight.

Observation:

My weight is 80kg. (80kg-g is more correct or accurate expression instead of 80kg. 80kg is the mass of my body, however 80kg-g is the weight of my body, that is the force that the gravity makes.)

When the eleator went down it pointed at 75kg.

When I pushed the first floor button at the twentieth floor, the scale indicated at 75kg for the first three floors.

The reason for the sequence is stabilization.

During the first three floors, acceleration of the elevator occured from zero to 5m/s.

However, after the first three floors, the elevator moved at a constant speed at 5m/s.

(Constant velocity means no acceleration or addition of force. However, acceleration indicates that there was an additional force affecting our body.)

Conclusion:

We can apply the Newton's Second Law to this experiment.

Summation of the external forces is equivalent to inertia force: F=ma.

(g=gravity, a=acceleration, 75g=measured value of weight during down of elevator, 80g=weight of my body at initial state, 80a=inertia force of my body)

75g-80g=80a

-5g=80a

therefore, a=-0.613m/s^2

a is the acceleration of the elevator.

Proving Bernoulli's Equation at Home(2)

Tools: Hairdryer, Stool, Sheet of Paper, Tape


Introduction:
As mentioned in the previous experiment, Bernoulli's Equation is used to predict real fluids such as air.
I performed one more experiments to help the reader fully understand the concept of Bernoulli's Equation.

Experiment 1: Hairdryer and a Sheep of Paper
Procedure:
1. Attach a sheet of paper on a stool.

2. Turn the hairdryer on and put it above the stool pointing the paper.

3. Observe the temporary stable position of the paper.

Discussion: According to the last experiment, Bernoulli's equation told us that when the velocity increases, pressure decreases.
Before using the hairdryer, the paper was bended downward due to gravity.
By blowing the air paralel to the seat of the stool, the sheet of paper moved upward.
This sequence indicates that the wind worked as a resisting force of gravity.
On step 3, the paper was fixed at a specific position, which indicates the balance of force between the wind and gravity.
The upward force which lifted the paper was cuased by the pressure difference between the two different sides of the sheet of paper.
Furthermore, the presure difference was caused by the flow of the fluid.
Since there was a flow from the hairdryer on the upper side of the paper, there was no flow under the sheet of paper.

Proving Bernoulli's Equation at Home(1)

Tools: Ping-pong ball, Hairdryer, Paper, Tape

Introduction:
Bernoulli’s equation describes the flow of ideal fluid.
This innovative equation helps us to predict the motion of real fluids such as air and water.
It is well known that when velocity of the fluid increases, pressure decreases to keep the balance in any part of the fluid.
We can prove the equation by the following two experiments by using only simple home materials.

Experiment 1: Hairdryer and Ping-pong Ball
Procedure:
1. Place a ping-pong ball on top of a hairdryer.

2. Turn the hairdryer on with the ping-pong ball at the top and observe.


Observation:
When the air was not coming out, it was difficult to balance the ball on the top of the hairdryer. Although the ball had variation in its positions, the ball did not fall from the top when the cool air blew out from the hairdryer. The ball was being balanced by the air.

Discussion:
The phenomenal can be explained through the delineation below.



The equation above is the Bernoulli’s equation.
It shows that when the velocity increases, pressure decreases, and vice versa.
On the depiction, vertical arrows indicate the velocity magnitude.
Horizontal arrows depict the magnitude of the pressure.
The picture on the left shows the ball’s instantaneously unstable position on the left side of the hairdryer.
The velocity on the right side of the ball instantly increases when the ball is on the left side of top of the hairdryer.
Consequently, the pressure on the left side increases which pushes the ball to the center or the right direction.
The same sequence occurs on the right side.
In conclusion, due to the restoring force to the ball, the ball can maintain its position around the center of the exit of the dryer.

I give thanks and partial credit to my father who advised me and helped me with the experiments.

Gravity and Zero Gravity

I am so glad that this blogspot is going better than I first imagined.

I hope this blog hopefully affects and answers the curiosities of other fellow student scientists.
To celebrate this occasion, for the first experiment, I decided to test about the thing that always affect us: Gravity.

Tools: Empty bottle, Needle, Water.

Introduction:

What is the difference between gravity and zero gravity.

The difference can be found from whether we can feel it or not.

Frankly, there is no such thing as zero gravity because gravity is everywhere.

The term zero gravity got its name because it is nearly impossible for us to feel or even see the existence of zero gravity.
Using three simple tools above, we can see the existence of no gravity.

Procedures:

1. Put a hole on an empty bottle.

2. Fill the bottle with water.

3. Check the water flow from the hole.

4. Drop the water bottle and observe the stoppage of water flow.

Observation:
The water flowed while holding. However, the flow stopped when the water expirienced a free fall.

Discussion:
The reason why water flowed from the bottle is because force uplifting the water from the bottom of the bottle and the gravity squeezed the water to flow out of the hole.
The water stopped flowing from the bottle because the force uplifting the water turned downward by the free fall.
Therefore, the water instantly experienced the state of being in zero gravity.

The First Step

To celebrate the opening of this blog, I decided to put an article.
Every project has an initiative step.
First step for experimenting is learning what can be used for scientific experiments around us. Therefore, I spent about thirty minutes to see what could be used for experiments.

I never realized how many things in our normal day live's tools can contribute to scientiifc experiments.
Since majority of my experiments are related to Physics, I decided to use use couple of rulers, tape, pliers for cutting and holding substances, and a weight meter.
I am pretty sure there are way more things that can be used for experiments around us.
But for now, these should be enough.

Introduction

I was never interested in Science before. Every time I heard the word "Science", I would cover my ears on the spot. However, ever since I chose my future major as Engineering and started giving small interests in science, I was fascinated by the deep logic within every concept of science. Having an erge to share my joy of learning science, I decided to record my progress and experiments on blogspot. I hope you enjoy reading my experiment journals.