Name:______

Stair Climbing Power

Problem: How much power do you use when climbing stairs?

Gathered Data:

Work = force x distance; work is measured in (N.m) Newton meters

Power = work/time; power is measured in (J/s) Joules per second

1J/s = 1 watt (W)

1 horsepower is the average power exerted by an average horse

1 horsepower = 746 J/s or 746 W

1 pound = 4.45 Newtons

1m = 100cm

Hypothesis:

Predict how your power output compares to that of an average horse. You can use a decimal or fraction if it suits you.

Procedure:

Recorded Data Table:

Weight (N)
Height of 1 stair (m)
Number of stairs
Total height of stairs (m)
Time of climb 1 (s)
Time of climb 2 (s)
Time of climb 3 (s)
Average time (s)

1.Work with a partner. Convert your weight from pounds to Newtons. Record your answer in the data table.

2.Measure the height of one stair step in centimeters. Convert centimeters to meters. Record in the data table.

3.Count the number of stairs including the landing in the middle as 1 and the landing at the top as 1. Multiply the total number by the height of each stair in meters. Record in the data table as total height of stairs.

4.Climb the stairs as quickly as you can. Record your time in seconds in the data table. Please be careful. After resting for a few minutes, repeat this step 2 times.

Analyze: (Show all math work)

1. Did you exert the same amount of effort during all three climbs? Explain.

2. Were the times of your 3 climbs roughly the same?

3. Calculate work for each climb. Multiply the total height of the stairs by your weight in Newtons.

4. Calculate the power of each climb. Divide your work by your time.

6. If you would have climbed slowly, how would that affect the power of your climb. Explain your answer mathematically, so look at how a larger time changes your answer in the power formula if the work stays the same.

7. Convert your power to watts.

8. Convert your power to horsepower.

9.What type of simple machine is stairs?

10. Explain how stairs make work easier?

Conclusion:

1.  Was your prediction true or false. Explain how your actual horsepower compared to the power of 1 average horse.

2.  How does your watt power compare to a 100watt light bulb.

3.  How long could you continue to exert the same amount of power before you would get tired and slow down?

4.  Why is it good to rely on generators for power instead of horses or humans?