an astronaut rides in a circular training center at 16m/s if the radius of the center is 8 what is his centripetal acceleration in m/s

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.

the doppler effect is used by weather forecasters to measure 

moving clouds