30 September 2014: Work and Power Lab 9

Objectives:

The purpose of this lab was for physics students to gain appreciation of their high metabolism, In this lab, the amount of work required to walk up a flight of stairs, to run up a flight of stairs, and to pull a heavy bag up the same distance will be calculated. Power will also be calculated.

Setup:

The only thing needed was this stair case located outside the physics building. Physics students were to first walk all the way up the stairs and time themselves. Then they would run all the way up the stairs and time themselves.

For the last part of this activity, a pulley system was set up on the railing of the second floor and physics students were to pull a bag of 5 kg up the distance they had just walked and run and time themselves.






Procedure:

The first thing we did was to calculate the height of one step and then count how many steps there were in total. With this information, we could find the height of the distance we were to walk and run.

We found that each step was 16.5 cm and there were 26 steps. So the height was 4.29 m.

We then walked up the steps and timed ourselves. Then we ran up the steps and timed ourselves.

My time was 10.29 s when walking and 8.65 s when running.










Then we pulled a 5 kg bag using a pulley system already set up for us and timed ourselves.

My time was 10.99 s.
















After everyone in the class had finished, we went inside to calculate our results.

Results:
Here are my results from running and walking up the stairs:

Running Work: 2672 J, Walking Work 2672 J, Running Power 309 Watts, Walking Power:260 Watts

 Here are my results from the pulley system:

Work 210 J, Power 19.1 Watts

Conclusions:
As you can see pulling the bag took the least amount of work and power. But to burn more calories, walking or running up the stairs would be best.

From this experiment I learned to appreciate my high metabolism. My favorite cheesecake ever is the Lemon Raspberry Cheesecake from Cheesecake Factory. This cheesecake however contains 730 Calories. If I consider every 1 J= 4186 Calories and that from taking the stairs to the second floor, I burn (2672/4186)=.64 Calories, I would have to climb 1140 flights of stairs to completely burn off that cheesecake. That would be like climbing the stairs in the empire state building 11 times!!