lab4powerONLIn

Lab 4: Power Objective: Calculate the work and power while walking and/or running up a flight of stairs. Materials/Equipment: stopwatch from phone, meter stick or ruler, weighing scale, flight of stairs. Note: Safety first! Perform this activity carefully. If you cannot run up the stairs, you can walk faster instead, or ask another person to do it. Five to six steps will be adequate. Theory: A simple way to measure the power output is to measure the time it takes a person with known weight to walk or run up a flight of stairs of known height. We then use the equations below to calculate for work and power. The value of power can then be compared to a horsepower (hp). A. Work ( Nm ∨ J )= Force ( N ) x displacement ( m ) B. Power ( J / s ∨ Watts )= Work ( J ) time ( s ) C. Horsepower ( hp )= Power ( J / s ∨ Watts ) 746 Watts hp Procedure: 1. Measure your weight (which is a force) in Newtons (N). Note: 1 pound (1 lb) = 4.49 N. 2. Measure the total height of the stairs in meters (m). This is the displacement. 3. Measure the time to walk up the flight of stairs. Complete three trials. 4. Measure the time to run up the flight of stairs. Complete three trials. 5. Calculate the work, power, and horsepower (hp) using the formula above. 6. Calculate all averages. 7. Write down all data in the table shown. Make sure to include units. J. Regalado 10/26/23 Page 1 of 4

Table 1. Data Walking Tria l Weight Displacemen t Time Work Power Hp 1 987 72 00:03:52 71,064 306.17W 0.41hp 2 987 72 00:03:89 71,064 310.50W 0.42hp 3 987 72 00:04:26 71,064 267.15W 0.36hp Ave --------- --------- 255.67s 71,064 294.61W 0.40hp Running Trial Weight Displacement Time Work Power Hp 1 987 72 00:02:41 71,064 441.55W 0.59hp 2 987 72 00:02:93 71,064 410.86W 0.55hp 3 987 72 00:02:84 71,064 433.61W 0.58hp Ave --------- --------- 192.67s 71,064 428.34W 0.57hp Questions: 1. Is there a difference in your work done while walking or running up a flight of stairs? Why or why not? The difference in work between walking and running up a flight of stairs comes from the time taken to complete the objective. Both activities require the same work to overcome gravitational force, running achieves this in less time compared to walking. This shorter duration of exertion during running results in less total work done, despite a higher power output due to my quicker pace. Although running expends more power per unit time, the total work done may be lower than when walking due to the faster pace. 2. Is there a difference in the power exerted while walking or running up a flight of stairs? Why or why not? When comparing walking and running upstairs, there’s a difference in the power exerted. Power is how fast you can do work, and it depends on how quickly you finish the task. While both walking and running need the same amount of effort to J. Regalado 10/26/23 Page 2 of 4

every trial. To make our results better next time, we should be more careful with pour measurements, try our best in every trial, and maybe use better timing devices. J. Regalado 10/26/23 Page 4 of 4