What does it mean when work is positive? velocity is greater than kinetic energy. kinetic energy is greater than velocity. the environment did work on an object. an object did work on the environment.

As we know by work energy theorem

Work done by all forces = change in Kinetic Energy

here if work done is positive then it means change in kinetic energy will be positive

So work is done on the object which will increase the kinetic energy of that object.

So here to increase the speed we can say that the surrounding is doing some work on it which will increase the speed.

So here correct answer must be

The environment is doing work on it.

C

Explanation:

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.