An automobile engine is 15 percent efficient. How many joules of input work are required to produce 15,000 joules of output work to move the car?

Answer:100,000JoulesExplanation:Efficiency of machines is the ratio of work done by machine (work output) to the work put in the machine (work input)Efficiency = Work output/Work inputGiven efficiency = 15%Work output = 15,000JoulesWork Input = ?Substituting in the formula of efficiency15% = 15,000/Work Input15/100 = 15,000/Work Input15× Work input = 15,000×10015 × Work input = 1,500,000Work input = 1,500,000/15Work input = 100,000Joules

15,000J/.15% = 100,000 JIf you want to check,Multiply 100,000 by .15 and you get 15,000 J