Nose

26/11/2012

Physical Science Report
Work and Power

Francisco J. Cerrato #6


Mr. Roberto Matute

9th Grade Section B

Purpose:

To find my work and power.Materials:

-Stopwatch
-Meter tape
-Notebook
-Stairs
-Scale

Procedure:

1) Use a scale to determine your weight in newtons. If your scale measures inpounds, multiply your weight by 4.45 N/lb.
2) With a classmate, use a stopwatch to time how long each of you takes to walk quickly up the stairs. Record your results.
3)Use a meter stick to measure the height of one step in meters. Multiply by the number of steps to calculate the height of the stairway.
4) Multiply your weight in newtonsby the height of the stairs in meters to find the work that you did in joules.
5) To express your power in watts, divide the work done in joules by the time in secondsthat you took to climb the stairs.

Convertions

155lbs÷2.21= 69.8kg
69.8kgx9.8= 684N
684Nx3.00m= 2052j
2052j÷7.87s= 260.7w

Time (s) | d(m) | Weight (lbs) |
7.87s |3.00m | 155lbs |

Fw (N) | Work (J) | Power(w) |
684N | 2052J | 260.7w |

Analysis

1) How would your power output change if you walked up the stairs faster? Ifyou realize something faster you apply my power in order to make it fast.
2) What would your power output be if you climbed the stairs in the same amount of time whilecarrying stacks of books weighing 20N? It would be more, 2112j.
3) Why did you use your weight as the force in the work equation? Because it is my body what I’m lifting upthe stairs.

Conclusion

I’ve concluded that my weight in newtons is: 684N. My work climbing the stairs in joules is: 2052J and lastly my power in watts is 260.7w