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.