Lab 10: Work and Power

   Lab 10: Work and Power 

I-Shou Lin, Kirk Paderes, Jorge Avalos

4/5/17

To perform physical " work" and calculate the power output and compare these results to power outputs of everyday electrical appliances. 

This laboratory activity is a hands on physical activity that's intended to measure the actual power output of a real person performing such tasks as lifting a backpack up a certain height and running up a flight of stairs. Afterwards, these calculated results from these physical activities can be compared to the typical power usage of modern everyday electrical appliances. In turn, we can get some perspective on the magnitude of the difference between the power output of a short physical activity and the power output of electrical appliances. 

We measured the power output for walking and running up a flight of stairs by measuring the height of a step, counting the total number of steps, and measuring the time it took to get up the stairs. For the power output of lifting a known mass up a certain distance, we measured the time it took. The height is calculated through multiplying the number of steps by the height of each step. 

( lifting backup up )

Measured Data 

Name of Activity	Time  ( seconds)
Lifting a known mass	17.67
Walking up the stairs	13.17
Running up the stairs	4.54

Mass of known mass	9 kg
Number of steps	25
Height of each step	0.169 meters
Weight of person going up the stairs	148 pounds =658.337 Newton

Calculated Results 

Power output	Numerical value
Lifting a known mass	21.1  watts
Walking up the stairs	211.2  watts
Running up the stairs	612.66  watts

p=w/t=m*g*h/t= (9 kg*9.8 m/s^2*25 steps* 0.169 m/step)/17.67 seconds= 21.1 watts

p=w/t= F*h/ t= (148 pound* 4.448 newton/pound * 25 steps* 0.169 m/ step) /13.17 s= 211.2 watts

In conclusion, this was an outdoor laboratory activity that featured realistic measurements of power output through the  execution of the tasks of lifting a known mass, walking up the stairs, and running up the stairs. The measurements that we took for the time and the height of each step are fairly accurate. Nevertheless, there's always a human reaction time and or negligence that can't be avoided.