A weightlifter lifts a barbell of mass 50 kg to a height of 2 m in 3 sec(take g=9.8m/s²​ a) What is the weight of the barbell?
b) What is the work done by the weightlifter?
c) Calculate the power developed by the weightlifter?

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.

d) physical means can be used to separate the components of air.

pecialized keyboards