Balance of Forces
In this section, you’ll have to bring along some energy to build bridges, lift people, and operate a lever.
When moving or changing the shape of objects, force is required to overcome natural forces like gravity. Ever since prehistoric times, people have been using tools – levers, pulleys, and other mechanical devices – to apply the necessary force to do work.
In structures like bridges and buildings, force has to be distributed so that they stay standing and withstand external pressures.
Wind farms and hydroelectric plants use the power of wind and water to create energy. They do so by converting the energy present in nature into a usable form like electricity. A portion, however, is turned into heat by friction and is usually not converted back into usable energy. People require energy in all aspects of everyday life, such as for lighting, heating, and transportation. Life without energy is not possible.