Energy to a 40% efficient engine

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To determine the energy transferred to a 40% efficient engine that accelerates a 1200 kg car from rest to 18 m/s, the work done by the engine must first be calculated. The kinetic energy of the car at 18 m/s is 108,000 joules. Since the engine is only 40% efficient, it means that 60% of the energy is lost, so the total energy required from burning gasoline is 270,000 joules. This calculation shows that not all energy produced by burning gasoline is utilized for work due to inefficiencies in the engine. Understanding these energy dynamics is crucial for evaluating engine performance and fuel efficiency.
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Homework Statement



A 40%-efficient car engine accelerates the 1200 kg car from rest to 18 m/s.
How much energy is transferred to the engine by burning gasoline?

any help is appreciated
 
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1. How much work is done by the engine?
2. Is all of the engine's energy being used to do that work? No, because the engine is not 100% efficient.
3. So how much energy must be released by burning in order for the engine to be able to do the amount of work calculated in (1) after 60% of said energy is thrown away?
 

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