Calculating work and power by climbing stairs

Lab – Stair Climbing Power

Purpose:

To see how power and work are affected by time.

Materials:

·

· Tape measure

· Stop watch

· Assistant

· 1 flight of stairs

Procedure:

1. Measure the height of one stair. Record this measurement in the data section below. Measure in meters if possible. If not, measure in feet and multiply that number by 0.305 to convert to meters.

2. Count the number of stairs. Record in the data section.

3. Multiply the number of stairs by the height of one stair in order to find the total height you will climb. Record this in the data section.

4. Calculate your weight in newtons by multiplying in your weight in pounds by 4.45. Record this in the data section.

5. While climbing stairs you are only doing work in the vertical direction. Even if you move horizontally you are not exerting a force in that direction. Use the data you’ve collected to calculate how much work you will do in climbing the entire staircase. Record this in the data section.

**If you are physically unable to climb stairs, reverse roles and record your assistants weight and time them while they climb the stairs.**

6. Have your assistant time you climbing the stairs twice, once slow and once faster. Record these times in the data section.

7. Use this data to calculate the power used for each climb.

If you want a chance for partial credit in case you make a mistake, include your work on another page.

Data:

Height of one stair = m

Number of stairs = stairs

Height climbed = _______ m

Your weight = _______ N

Work done = ______ J

SLOW

Time = ______ s

Power output = ______ W

Power output = ______ kW

FAST

Time = ______ s

Power output = ______ W

Power output = ______ kW

To convert from Watts to kW, divide by 1000.

1. How does your power output compare to those of a 100 W light bulb?

2. How does your power output compare to an average horse (746 W)?

3. Did the speed of your climb affect the amount of work you did? Why or Why not?