A heat engine has a total heat input of 1.3 kJ and a thermal efficiency of 35 percent. How much work will it produce

455Joules

Explanation:

Efficiency is expressed as;

Efficiency = Work output/Work input × 100%

Given

Efficiency = 35%

Work input = 1.3kJ = 1300Joules

Required

Work output

Substitute into the formula to get work output as shown:

35 = work output/1300 × 100

35 = work output/13

Work output = 35×13

Work output = 455Joules

Hence the machine will produce 455Joules of work

gravity

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.