A heat engine takes heat QH from a hot reservoir and uses part of this energy to perform work W. Assuming that QH cannot be changed, how can the efficiency of the engine be improved? (a)Decrease the work W, the heat QC rejected to the cold reservoir remaining unchanged. (b)Increase the work W, the heat QC rejected to the cold reservoir increasing as a result. (c)Increase the work W, the heat QC rejected to the cold reservoir remaining unchanged. (d)Decrease the work W, the heat QC rejected to the cold reservoir decreasing as a result. (e)Increase the work W, the heat QC rejected to the cold reservoir decreasing as a result.

increasing transnational kinetic energy. because the transnational kinetic energy formula consists of only two variables, mass and velocity, increasing one of those properties is the only way to increase an object's transnational kinetic energy. increases to mass and velocity, however, do not have the same impact.

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.