Method: First measure a person’s weight in pounds (lbs) and convert this to kilograms (kg) by dividing it by 2.205, this would be their mass. Next calculate a person’s weight in newtons by multiplying the mass by gravity (10m/s²). Then measure the vertical distance with the yard stick in meters (m) to travel by measuring each step individually and adding them together, this sum is your height. Now calculate their work done by multiplying the weight of the person (N) by the height of the stairs (m). Next time with the stop clock in seconds (s) how long it takes the person to climb the stairs. Finally calculate the power (J) developed by the person by dividing the work done (J) by the time it took them to climb the stairs (s)
Results:
Mass of person (g) = Pounds(lbs) / 2.205
Weight of Person (N) = Mass of person (g) x Gravity (10m/s²)
Height of Stairs (m) = Sum of height of each vertical step
Work Done (J) = Weight of person (N) x Height (m)
Power (J) = Work Done (J) / Time (S)
Conclusion:
In trail number one, the person weighed around 101 pounds(lbs) whose mass was then converted into grams by dividing her weight in pounds (101lbs) by 2.205 which resulted in 45.80g. Their weight in newtons was calculated by multiplying her mass in grams (g) by the force of gravity assuming it was10m/s², this gave us a value of 458N With the yard stick we measured each individual vertical step in centimeters(cm), added them together and divided the sum by 1000 to convert the sum into meters(m), this gave us a value of 1.739m The vertical height was measured because the persons will have to lift their body against the vertical force of gravity. To achieve the person’s work done in joules (J), we multiplied the weight of the person 458N by the distance in height they traveled, 1.739m which resulted in 796.46200J. Since power equals force multiplied by distance divided by time, the same applied in this experiment. The force is the person’s weight in newtons (458N), the distance is the vertical height (1.739m) and the time is (2.13s) which gave us a resulting power in joules of 373.9258J. In trail four, this is where the most amount power is developed (860.6393J) and in trial three this is where the least amount of power is developed (341.7482), creating a difference of 518.8911J. The person in trail four used more power because of the larger amount of work done (2168.8112J) in a lesser time span (2.52s) and the person in trail three used less power because of the smaller amount of work done(1025.2448J) in a greater time span (3.0s). The difference between trail four’s work done and trail three’s work done is 1143.5664J and the difference between trail four’s time and trail three’s time is 0.08s. The person in trail four had the most work done because they had more weight to lift themself against the force of gravity up the vertical distance and trial three’s person had the least amount of work done because they had the least amount of weight to lift themself against gravity up the steps. Therefore because of the greater amount of work done in trail four, the amount of power is greater and because of the lesser amount of work done in trail four, the amount of power lesser. In conclusion, if the amount of work done is high as well as the time or the work done is low and the time taken is quicker then the power developed would be greater. But if the work done is high and the time taken is longer or if the work done is low as well ad the time, then power would be lesser.
Errors that might have occurred could have been systematic errors. Incorrect measurements of the height of the vertical distance is a significant source of error which would affect the amount of power developed. A way to improve the accuracy of your measurements would be to make sure you are measuring with an accurate yard stick to read the measurement at eye level and to ask for a second opinion on your judgment. Another source of error could be a miscalculation of the mass of the person in grams(g), the weight of the person in newtons(N), the height in meters of the vertical distance(m), the work done(J) or the power developed(N). To improve the accuracy of your calculations, write down each figure to multiply, divide or add with appropriate labels in your table. Next, take your time performing the necessary calculations slowly on a calculator. To make sure the calculations are correct, have a friend check it over with a different calculator. You might also end up with inaccurate calculations because of rounding off figures. To improve this, write down the exact figure up to a certain decimal place and be consistent about the decimal place with each figure to maintain a fairly accurate result. Another source of error is inaccurate time keeping. In order to improve on more accurate time spans, you should start timing as soon as the person lifts their leg to climb the first step instead of starting the stop clock as soon as a signal to commence climbing the steps is given. If you were to start the stop clock along with the commencement signal, you will acquire extra seconds or nanoseconds because of the time it takes for the person to react to the signal, this could affect your resulting power developed calculations.
