Question

An old lorry is 20% efficient at converting the

Answer 1

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;

$Energy \ Efficiency = \dfrac{Energy \ produced }{Total \ Energy \ Taken \ In \ or \ Used} \times 100$

Therefore, the for the old lorry, we have;

$20\% = \dfrac{M.E. \ Produced}{600 \ Joules} \times 100$

∴ 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