How do we measure or think of speed in the united states?

I'm not sure what you mean by "think of speed", but the way we measure it is by plugging the numbers into this formula: distance divided by time. If you are trying to find an average speed, then your formula would be: total distance divided by total time. I hope this helped!:)

dopamine..

"it was found that some people who were taking the drug l-dopa to raise their levels of dopamine were developing schizophrenic-like symptoms supporting research a strength of the dopamine hypothesis is that there are many studies which have shown support for the neurochemical explanation."

truck y has a greater velocity than truck x.