Lab # ? Human Power

Human Power

Purpose:
 To determine the power output of a person.
Equipment:
 Two meter sticks, stopwatch, kilogram bathroom scale.
Introduction:
 Power is defined to be the rate at which work is done or equivalently, the rate at which energy is converted from one form to another. In In this experiment we did some work by climbing from the first floor of the science building to the second floor. By measuring the vertical height climbed and knowing our mass, we were able to calculate our gravitational potential energy:
m=mass
g= acceleration
h= vertical height gained

DeltaPE=mgh

To calculate Power= (delta PE)/ (delta t)

Procedure:
We determined each member's mass by weighing on a scale and used Logger Pro to convert our weight in kilograms to Newtons. We measured the vertical distance between the ground floor and the second floor of the science building by using a 2m meter stick. We recoded 4.26 m for all groups. A record keeper was assigned and the groups took turns to record the time that each team member took to run/walk up the stairs.
Then we calculated the personal power output in watts with the data collected.
The average of the entire class was 541watts.

Conclusion:
Using the hand railing to assist you in your climbing up the stairs is not necessarily a source of error so in this case it is not important. This is because it only increases the amount of energy needed to get up the stairs, it changes the results but does not contribute an incorrect value. The same goes for changing the time it takes for the person to climb up the stairs, skipping steps, walking/running, jumping off; still does not mean the value is incorrect, it just changes the results.
Some of the real sources of error could be measuring the height from the ground floor to the second floor, measuring the weight of each member, significant figure rounding errors, timing, etc., since this can directly change our calculation and give us an incorrect value. Also,
An important source of error that was not mention in the class discussion was the fact that we only took one trial per person and not two as it was directed on the lab, meaning that we didn't have an average to make sure the value for the "human power" was as accurate as possible. For sample calculation and data table see below.