A 1000 kg cars on constant speed of 25 m/s . What is the magnitude of average netforce, is required to slowing car to 12.5 m/s within 15 seconds?

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 answer is 12 as i may remember

: )