contestada

An old lorry is 20% efficient at converting the
chemical energy in the diesel into useful
mechanical energy. How many joules of
mechanical energy are produced when 600
joules of chemical energy have been used by
the engine?

Respuesta :

Answer:

The amount of mechanical energy produced by the old lorry when 600 Joules of chemical energy have been used by the engine, M.E. is 120 Joules

Explanation:

The question is a word problem on the relationship between energy efficiency and energy consumption

The given parameters of the old lorry are;

The chemical energy to mechanical energy conversion efficiency of the old lorry = 20%

The amount of chemical energy used by the engine = 600 joules

Let 'M.E.' represent the amount of mechanical energy produced by the old lorry, we have;

[tex]Energy \ Efficiency = \dfrac{Energy \ produced }{Total \ Energy \ Taken \ In \ or \ Used} \times 100[/tex]

Therefore, the for the old lorry, we have;

[tex]20\% = \dfrac{M.E. \ Produced}{600 \ Joules} \times 100[/tex]

∴ M.E. Produced = 20/100 × 600 J = 120 J

The amount of mechanical energy produced by the old lorry when 600 Joules of chemical energy have been used by the engine, M.E. = 120 Joules