Explanation
By using a lever of the sort shown in the above illustration, you can increase the output force (moving the load) applying the same amount of, or possibly less, input force (effort).
Battery companies make impressive claims about how long their batteries will last. A student decided to test the running time of different batteries to determine which battery lasts the longest. The student tested 6 different batteries, 4 brand name and 2 generic, using flashlights. The results show that the battery referred to as Name Brand A lasted the longest, with 101 hours of runtime:
Flashlight | Battery | Runtime in hours |
Gearlight Super Light | Name Brand A | 101 |
SureFire | Name Brand B | 99 |
Maglight | Name Brand C | 80 |
Bright Star | Name Brand D | 75 |
SureFire | Generic A | 30 |
Bright Star | Generic B | 29 |
It could be argued that this experiment was not set up using proper experimental protocol. What would need to change in the experiment for the results to be valid?