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FIRST YEAR SCIENCE 



energy furnished by the sun. Plants cannot grow without 

 the energy furnished by the sunlight, and animals could not 

 live were it not for the energy furnished them by the 

 plants. 



For untold ages plants utilized the sun's energy and 

 stored it up. It was preserved in the remains of plants 

 in the form of coal. This coal is now being burned to 

 furnish power to carry on man's industries. The water 

 which the sun has evaporated and carried by cloud and 

 shower to the mountain lake is stored there and has po- 

 tential energy. It is ready to run down the valleys chang- 

 ing its potential energy into kinetic and doing work. We 

 often think that there are many different sources of energy 

 such as wood, coal, oil, waterpower and others, but when 

 these are traced back, their energy is found to have come 

 from one source, the sun. 



Energy may readily be changed into different forms, as 

 when the steam engine transforms the energy in coal into 



TRANSFORMATION OF ENERGY. 



mechanical energy, or when this mechanical energy is 

 changed by the dynamo into electrical energy. The most 

 careful investigations have shown, however, that although 

 its form may change, energy can never be destroyed. 



