Under what circumstances is it appropriate to
experiment with human beings?

The circumstances are that when the subject is defined as an individual who is observed or experimented with by an investigator. The human has to be dead and can only be used to try to find a cure for any type of disease or it can also be used to figure out the cause of the person's death.

Explanation:

I don't know very much about experimenting on human beings, but I hope this helps! :3

no, because those are both different running competitions. while distance runners train their legs and their lungs to run long amounts of time, the sprinters are training their legs and their lungs to give all they have in the little amount of area they need to cover. the brain also plays a huge part in all of this.

the brain is the only thing in your body that sends messages to your body telling you to run. if you are a long distance runner and you have the mind set of a sprinter, you will not get anywhere. if you have a long distance mind set and you have to run 200m in 20 seconds then you will not make it in time.