29-Sept-2014: Determining Work with different masses (stairs & pulley)

Purpose:
The purpose of this lab was to determine the work and power generated by walking up a set of stairs and pulling a mass upward roughly the same distance.

Apparatus:
The apparatus were the stairs located on the north side of the Science building 60 as well as the second floor balcony where a pulley was placed with a mass suspended by rope.

Experiment:
The first step of the lab was to record the distances that would be traveled up the stairs by the student and up the balcony by the pulley. We recorded 26 steps up the stairs each measuring 16.5 centimeters in height which resulted in a distance of 4.29 meters that were being traveled from the bottom of the stairs to the top. Once the distance was determined we conducted the experiment by first travelling up the stairs at slow pace then a faster pace and recording the duration of the trip. Once we collected all of the necessary data we followed to next experiment of the pulley and mass.

Just as the previous experiment we recorded the distance traveled but in this case it was from the floor to the balcony railing and using a mass as seen in the apparatus. Using a 3 meter stick we recorded the distance as 5.3 meters. Following the distance collection we proceeded to conduct the experiment by pulling the mass upward and recorded the time taken to reach the top and the amount of the mass.

After collecting all the data we continued back inside in order to calculate the work and power

Here is the data used:

Stairs

• Mass = 180 lb. = 81.8 kg.
• Distance = 4.29 m
• Time 1 = 13.14 s
• Time 2 = 6.6 s

Pulley

• Mass = 6 kg
• Distance = 5.3 m
• Time = 5.6 s

Calculations:

Using the definition of work: Work = Force x Distance we determined how much work was done to travel up the stairs:

Work = (81.8 kg) * (9.81 m/s^2) * (4.29 m)

Work = 3442.5 Joules

Now for power we used: Power = Work / Time to determine the power generated from strolling up the stairs to running up the stairs:

Power = (3443.5 J) / (13.14 s)

Power = 261.9 watts

Power = (3443.5 J) / (6.6 s)

Power = 521.6 watts

Next we calculated the values of work and power for the pulley system:

Work = (6 kg) * (9.81 m/s^2) * (5.3 m)

Work = 311.9 Joules

Power = (311.9 J) / (5.6 s)

Power = 55.7 watts

Conclusion:

After solving for the values of work and power for each experiment i can be concluded that traveling up the stairs is more effective at burning calories than that of the pulley system.