All of the following would be questions that could be scientifically investigated except:

"What is the best advice a parent can give a child?"

Explanation:

The other answers have one clear response. Ex: Orange popsicles melt faster than grape popsicles. That would be a fact.

But parental advice can vary, depending on your opinion. I may say that all parents must teach their children not to talk to strangers, while someone else may say that parents should advice their kids to treat everyone fairly. Nothing can be proven as the only appropriate response.

Hope this helps!

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s