When automobiles are designed, engineers try to maximize their fuel efficiency. Even with modern technology, today's most efficient vehicles can only attain about 30% efficiency. That means of all the chemical energy of the fuel put into an automobile, only 30% of the fuel results in car motion. Which statement best explains why this happens?

Much of the energy is destroyed.

Most of the energy is transformed into mass.

Most of the energy becomes chemical energy.

Much of the energy is transformed into heat.

Much of the energy is transformed into heat.

In the diagram below, light from the Sun strikes a beach (Z). The beach sand gains heat then warms the air that is immediately above it (X) and the sand that is immediately below it (Y).The warm air rises and is replaced by cool air (W). Which point indicates convective heat transfer?

(1 point)
Responses

Y
Y

Z
Z

W
W

X
X
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The correct statement that explains why today's most efficient vehicles can only attain about 30% efficiency is: "Much of the energy is transformed into heat."

The statement that best explains why today's most efficient vehicles can only achieve about 30% efficiency is "Much of the energy is transformed into heat." When fuel is burned inside an automobile engine, it undergoes a combustion process where the chemical energy stored in the fuel is converted into thermal energy (heat). However, a significant portion of this thermal energy is lost as waste heat through the cooling system and the exhaust system. This heat energy is not effectively converted into useful mechanical work that propels the car forward. Therefore, the efficiency of the engine is limited because a large amount of the fuel's energy is dissipated as heat rather than being harnessed for actual motion.